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Air-Vent Passageway

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Why this trope doesn't work in Real Life.

"Buildings always seem to house gigantic vertical shafts where the hero can hide and access any other room in the entire building, and where the enemy never seems to look for them."
"Hollywood Rule Book," Vanity Fair

It's the only move a villain can make that's stupider than Locking MacGyver in the Store Cupboard (or any room with a bed). When heroes find themselves trapped in a room with all doors and windows locked, the quickest exit is always through the ventilation duct. Air vents also work excellently in reverse for breaking in and infiltrating a facility.

Openings are within reach, covers require little effort to remove, the ducts themselves can support the weight of a person and are wide enough in diameter to allow an adult to pass through, there are no internal obstacles except for the occasional Deadly Rotary Fan blocking the branching corridors, they are free of normal sheet metal's dangerously sharp edges, they are totally soundproof, there are no security cameras, and there's never a lack of light or chance of getting lost unless the plot calls for it.


And the escapee always emerges without having picked up so much as a speck of dust.

A smart villain would have smaller air ducts, post guards around the openings, or line their ducts with barbed wire and broken glass. It even appears near the top of the Evil Overlord List.

This is practically a Discredited Trope by now, and requires some effort to justify if it's to be used seriously. Despite that, it does happen once in a while in real life. Frank Morris and his accomplices escaped from Alcatraz using the large ventilation duct that led them to the roof. And that leads to knowing that large industrial, commercial and construction complexes need to have enough air flow to manage their needs (like hot equipment or extremely deep locations for personnel use), which often requires a large ventilation system. It's not practical in general use though, still, as grates bolted in place still block your entrance and getting towards office space will shrink the vents.


Some large universities (MIT and Caltech in particular) have longstanding "steam tunnel spelunkers" clubs, who often use air ducts (among other things) for exploring, getting around campus quickly, or pulling pranks. Readers of this trope should be advised that this is extremely dangerous, not to mention illegal — steam tunnels are usually hot, cramped, and frequently criss-crossed by scalding-hot piping, and explorers face trespassing charges and possible academic sanctions if they're discovered withinnote . Disney, meanwhile, has taken the concept of utility tunnels and turned them into the Utilidor system used at their parks, which allows staff to quickly move from one area to another without ever needing to break the suspension of disbelief by wandering about in their uniform on the surface.

Most Real Life attempts to sneak in or out via air duct aren't very successful, since people tend to be fairly large and ducts tend to be fairly small, plus the fact that air can bend at ninety degree angles and fit through grates much more readily. There have been numerous cases where enterprising criminals have attempted to rob a store by sneaking through the ducts and end up getting stuck. The usual ending is the embarrassed criminal being either pulled or cut out of the duct by the fire department and then promptly handed over to the authorities.

Compare Absurdly Spacious Sewer for a similar trope which takes place beneath buildings rather than in them. Also see Chimney Entry.


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    Anime & Manga 
  • In "Turnabout Prophecy" of the Ace Attorney manga, this is averted. The ventilation pipes themselves are too small to crawl in, but it is possible to crawl in the area where the pipes are.
  • In AKIRA, Kaneda tries to escape custody through the ventilation duct. He doesn't get far though.
  • In Axis Powers Hetalia, Paint it White!: Italy, Germany, and Japan pull one of these in order to escape the aliens currently chasing them. May or may not be justified because they were in an alien mothership, with air vents about the size of an average person. They DID fall through at one point, and Germany got quite a few scratches to the face.
  • Amusingly downplayed by Jody Hayward in El Cazador de la Bruja. She uses the vents to sneak into Rosenberg's office only to find that her hips are slightly too large to fit through them.
  • Ryō and Saeko sneak into a jewel exhibit this way in City Hunter. Ryō gets a heel in his forehead as a reward for his overly ardent Male Gaze.
  • Justified on two occasions in Dance in the Vampire Bund.
    • Akira making it through the massive vents and tunnels of the underground city beneath Tokyo Landfill #1 to escape the assassins hunting him makes sense (and he finds himself reminding his prepubescent rescuers that he is not as compact as they are).
    • In an inversion from volume 7, after a Manchurian Agent locks down Mina's skyscraper-cum-palace the only person who can get to the security center via the way-too-small-for-anything-remotely-human vents is Vera (who turns into mist and is obliged to leave her clothes behind).
  • While searching an enemy ship in Fairy Tail the Exceeds (who are about the size of a cat) are shown crawling through an air vent, wondering about the necessity of it and complaining about how narrow it is. When they ask why they're in there instead of searching the rooms like a normal person, Happy says "No particular reason".
  • Franken Fran has to cut off at least half her body in order to pull off a vent escape.
  • Justified in Fullmetal Alchemist: shrimpy Edward is the only character who can fit in the air vents, and for him it's a tight fit. Which leads to further comedy as Ed has a complex for being The Napoleon.
  • Futari wa Pretty Cure episode 10. Nagisa needs to get into a store being robbed so she can meet Honoka, since they have to be together to transform. Extra points for doing it in the course of about five seconds with no equipment.
  • In G Gundam's second episode, Domon sneaks through the ducts of Madison Square Garden and ambushes Chibodee's boxing opponent so he can take his place. In the 2010 manga re-telling, the sequence is Played for Laughs instead: Domon intends to go to Chibodee and challenge him, but ends up in the opponent's room because he got lost. He then tries to play himself off as an autograph hound. It doesn't work, and after knocking the guy out he decides to take his place.
  • Mamoru and Volfogg do this in GaoGaiGar when their base is taken over by a computer-hacking Zonder. Mamoru is a nine-year-old, but Volfogg is a robot that transforms into a police car.
  • Ghost in the Shell: Stand Alone Complex
    • Like the opening of season 1, the opening of season 2 is all about showing off the awesome skills of Section 9 while providing a reason for the unit's reactivation. The regular SWAT unit attempts an assault on the Chinese embassy through the air vents, but spectacularly fails with one officer dead and another being added to the terrorists' hostages. Seeing these poor results, his superiors immediately give Aramaki the green light to send in his team and get the job done.
    • When Batou is snooping around in Zaitsev's office, he hides in the ducts when Zaitsev returns unexpectedly.
    • 2nd GIG episode "Ambivalence". Major Kusanagi physically breaks into the Cabinet Intelligence Agency's building to cyberhack into its Decatonchire server. After the Big Bad Goda discovers the breach and alerts security, she escapes the building by entering the air system via a opening in the ceiling.
  • Hellsing
    • Integra does this to hide from her uncle.
    • Seras and Walter also use this to avoid a confrontation with the Valentine brothers.
    • Walter actually makes a point of reminding Integra that she used the vents to hide, so it's possible that they were deliberately designed with the purpose of allowing people to move throughout the mansion and avoid enemies in mind.
  • Done in Hunter × Hunter, though the character doing this (Queen Oito, after Kurapika grants her Nen abilities) is mind-controlling a cockroach, making it more plausible than normal. The cockroach finds Prince Tserriednich's Nen Beast within the ducts, forcing Oito to perform a quick mind-recall back to herself before the Nen Beast eats the cockroach.
  • In JoJo's Bizarre Adventure: Battle Tendency, the Pillar Man Santana manages to get through a 4-by-20-inch, grate-covered vent by pulverizing every bone in his body and flattening himself until he can slip through. Thereafter, the Nazi research team does not live long enough to learn that Evil Is Not a Toy.
  • Subverted with glee in Mnemosyne: Slender (though busty) Action Girl Rin Asougi decides to infiltrate an empty research laboratory by going through the ducts. She predicts the lasers and makes them visible by filling the cramped ventilation duct with smoke from a cigarette, and then proceeds to slip under the lasers... until her butt catches the laser, setting off all the alarms. Cue Rin's capture and... Squick.
  • In Monster, Johan and Anna/Nina's mother escapes through a rather small-looking air vent not just pregnant but in labor.
  • Neon Genesis Evangelion: Asuka, Rei, and Shinji were forced to use this route to get into the Geo-Front during a power outage when none of the doors would open. The air vent entrance also lampshaded the Male Gaze when Asuka kept kicking Shinji for "looking ahead." Later in the episode, we are treated to the sight of Humongous Mecha escaping via (humongous) air ducts. The geofront itself is an immense underground open space, hence the need for extremely large duct shafts to the surface to keep the air fresh.
  • Done once in Rave Master though by a creature who must be light, because he floats when he sleeps, and something that may be a small dog.
  • In Shugo Chara!, Kiseki and Yoru escape from a locked room this way. Justified since the Shugo Charas in that series are small enough to fit in normal air ducts.
  • Successfully done by Tsukiyo in The World God Only Knows, but small as she is she still couldn't have pulled it off normally. Rather, she was shrunk down to the size of a doll and it was still a pretty tight fit.
  • Mokuba Kaiba once escaped from the Big 5 this way in Yu-Gi-Oh! At least he's a fairly small kid, more likely to fit and all that.
  • In Yu-Gi-Oh! R, Jounouchi and Honda avoid some Mooks this way. Lampshaded by Jou, who complains about how claustrophobic it is and keeps getting accidentally kicked in the face by Honda.
  • In Yu-Gi-Oh! ARC-V, a few characters escape from prison this way. It takes them a while to remove the grate and the fans inside, and a guard catches them, but they manage to bluff that they had been ordered to repair it.

    Audio Plays 
  • Lampshaded in the Big Finish Doctor Who audio adventure "The Apocalypse Element".
    Evelyn: There must be some other way. An inspection hatch, or even, God help us, a ventilation shaft!
  • Played straight in the BBC Radio 4 adaptation of the Raffles story "The Gift of the Emperor". Raffles uses the cruise ship's ventilation system to sneak between rooms. The book (which was written in the nineteenth century) employs a more era-appropriate chimney-drop.

    Comic Books 
  • An example of a villain using this trope is found in Marvel's 1990s series Sleepwalker, when Serial Killer Jeremy Roscoe, after freeing himself from his restraints, climbs into the ducts to escape the prison hospital where he was being held. Probably not as bad as some of the other examples, since by that time the alarms were already activated and Roscoe's only concern was getting out by the fastest route possible.
  • Spider-Man does this every now and again. In an interesting variation, however, he usually does it when he's breaking into a place, rather than trying to escape.
  • Kei tries this in The Dirty Pair series Biohazard. But she gets stuck when her full, child-bearing hips won't fit. Mmmm. It's a Shout-Out to one of the TV episodes. Also contains Yuri's wonderful 4th-wall-leaning/Lampshade Hanging from her outside POV: "Been hitting the cheesecake a little too hard, hmm?"
  • In the fourth issue of Gotham City Garage, Supergirl, Nightwing and Catwoman crawl into a vent to break into a secret facility belonging to Lex Luthor.
  • Averted in Y: The Last Man when Agent 355 and Yorick are breaking into a hotel in Sydney (surrounded by barbed wire and armed security due to the increase in drug-related crime After the End).
    Agent 355: You said we'd be able to use the air conditioning vents. They're six inches by four inches.
    Yorick: Yeah, well, I overestimated the amount of... air this place might need...
  • Reed Richards of the Fantastic Four does this now and again as well. Justified in that his powers are to stretch his body to any length, and width.
  • Batman
    • Scarecrow escaped Arkham Asylum this way. Justified in that this villain has always been a skinny britches. And it's Arkham Asylum.
    • Used again in the 1980s Frank Miller envisioning of Batman. True, this time it was an arranged "escape" — with both Batman and Commissioner Gordon in on the act of breaking a villain out of an ordinary holding cell. However, this time the prisoner is the hulking Mutant leader, a man built enough to take on Batman in hand-to-hand combat. (The breakout was so that Batman could have a rematch, after also arranging for the entire Mutant gang to be on hand to watch their leader get taught a lesson in messing with the Batman.)
    • In Robin Series Damain worked his way to the heart of the Batcave using the air vents when he was trying to escape from his grandfather. He wasn't able to enter the vents until he'd already made it into the cave and past layers of security, and it wasn't sneaky at all as Tim was well aware of his location and waiting for him when he exited.
  • Ms. Tree makes this escape as part of her "Die Hard" on an X plot in the "New Year's Evil" story.
  • In Dreamkeepers, Namah and Mace (and Whip) are both partial to this trope.
  • Used in a Bash Street Kids strip in The Beano which saw Fatty, Plug and Smiffy crawl into a vent in an attempt to steal a key off Teacher.
  • Subverted in "Earthquake", an issue of Paperinik New Adventures: Paperinik must get around a closed door. Being Genre Savvy, he tries to go into an airvent, remarking: "This always works in the movies!" Being a Pint-Sized Powerhouse, he can crawl in, but his large shield gets stuck.
  • Discussed by Catwoman, who explains that extra and unnecessarily large vents and crawlspaces are common in Gotham as a result of the widespread corruption that allows contractors to get paid for extra construction on municipal buildings, then further cautions that most of these are undependable and poorly made because they're just there to justify extra budget allocations and the contractors weren't concerned with their use and upkeep.
  • Played with in Diabolik: Some houses may have or have not vents sufficiently large, resulting in Diabolik and Eva (extremely agile people) either climbing in themselves or using a remote-controlled robot to reach the safe or vault.
    • The series being what it is, one of Diabolik's targets put together a Diabolik-proof vault, whose security measures included vents too small for Diabolik and Eva and an always active jammer in case someone tried with a remote-controlled robot. Thus you can understand how surprised were Diabolik and Ginko when someone still stole from the vault... At least until Diabolik found out it had been the owner's daughter, a very intelligent child who wanted her father's attention.
  • In Flare, Raven Gold the party crasher uses one to sneak into Max Krueger's office toward the bottom of this page.
  • Subverted in the IDW continuation of G.I. Joe: A Real American Hero. Bombstrike is captured by the Red Shadows and imprisoned in their research facility in Olliestan. When the guards notice through the vision panel in the door that her cell appears to be empty, they throw in a flash-bang grenade before entering (in case she's hiding just out of view from the peephole), only to find the cell is empty and the grate over the air vent is dislodged. The guards do question how she fit through there, but run off to raise the alert, leaving the cell door wide open. Once it's all clear, Bombstrike emerges from above the ceiling tiles in the cell and makes her way out through the corridor.
  • Mickey Mouse Comic Universe:

    Comic Strips 
  • In a series of Get Fuzzy strips, Bucky tried this tactic to reach the ferret in the next apartment. While he fit fine (because he's a cat) he ended up getting lost and having to call for help... and Satchel mistook the voice coming out of the walls for God. Hilarity Ensues.
  • In a Dilbert strip, Alice tells naive intern Asok, "You must climb through the Jeffries tubes to reach the furnace before it fries us all!" He gets stuck half-way in, but that was her plan: "Today, Asok learns that life is not like Star Trek." With Asok's lower body hanging out of the vent, Alice puts up a sign that reads "Spank the Intern $.50".
    • Similarly, the boss has to hide in the ducts when his security clearance is revoked. He gets stuck and is presumed dead, resulting in the construction of a 'totally cool device to increase the duct pressure and propel his carcass into the stratosphere'.

    Fan Works 
  • Code Wings 3.0: Jeremie and the others use the ventilation shaft to their new room to evade the whitecoats and Erasers.
  • Epic: The Third Survivor: Sherry spends several chapters roaming around the police station's ventilation system to evade the zombies.
  • This is the method that Draco uses to get the Death Eaters into Hogwarts in A Very Potter Musical.
  • Zig-Zagged in a weirdly justified way in Heroes of the Desk—the air vents at a university facility are not large enough for a full-size human (averted), but a 14" tall Hero character can crawl through them (played straight—supercomputing buildings need a lot of cooling).
  • One chapter of the Kim Possible fanfic I Think Some Serious Physics Just Happened has a nice deconstruction of the trope when Ron, dropped into the real world, sneaks into a library through the airvents and naturally gets dirty while crawling through them. Then he starts to wonder why the vents in the supervillains' lairs were never less than spotless. Who was cleaning them? How? Why?
    • It's often a good idea to clean out ventilation systems to increase air-flow efficiency, reduce allergens, and stop a significant layer of dust accumulating on everything in the building every night. Particularly in warehouses with the giant ventilation systems that someone could actually crawl through.
    • Or there might simply be enough traffic in the ventilation system of the average villain lair to prevent dust gathering... Let's face it, those bases usually last a month or three, and see twenty-odd people getting around by air vents in that timeframe.
  • In another Kim Possible fanfic, To Bebe or not to Bebe, Kim and Ron are captured by a surprisingly competent villain who not only has air vents too small to crawl through, but also took all their equipment and destroyed it rather than leave it out to pick up when they escape.
  • HERZ: In chapter 4 Kurumi used a ventilation shaft to reach Terminal Dogma after being told it was off-limits.
    The grill made a tremendous clanging sound as it crashed onto the floor. Kurumi, in her UNIPF combat fatigues, emerged from the ventilation shaft. "Terminal Dogma is off-limits, my ass."
  • The Second Try: Shinji used a ventilation shaft to sneak out and back in NERV in the second-to-last chapter.
  • Nobody Dies: Terrifying!Rei's favorite method of Stealth Hi/Bye is to drop out of NERV's any ventilation system. He~eeey. Oh, Crap!. Running now. Later revealed to be a trait common to all Lilith-based Nephilem, as when Shinji is temporarily turned into a Nephilem, he suddenly gets good at zipping through vents too. Kensuke is picking it up as well, due to his... "friendship" with Rei.
  • Used in the Portal 2 fanfic Test of Humanity, though it's more of an "incinerator exhaust pipe escape". Subverted in that Wheatley is too fat to fit all the way through and ends up stuck, causing the pipe to explode from the built-up pressure.
  • In Fallout: Equestria - Pink Eyes, the main character Puppysmiles is just a little filly, meaning it's easier to crawl around in tight spaces. She uses this to enter a locked-down fortress to search for her mom.
  • Examples from the Calvinverse:
  • Queen of All Oni: Drago uses the air vents to break into Section 13. He calls it a cliche, and expresses disappointment that the Section 13 of the present isn't on the same level as the one in his time.
    • During the Final Battle, Jade and Hebi use the chaos of her forces' invasion of Section 13 as a distraction to sneak into the air vents and use them to get to the Vault unseen.
  • Earth and Sky: After Chrysalis is arrested and thrown in the dungeon in Los Pegasus, she slips free of her chains by molting to filly-size and then crawls out through a vent. Even then, it only works because, as Luna points out, her carapace hasn't hardened yet, allowing her to squeeze through the tight space.
  • Hitman Miami: In chapter 8, the only way into the target's office, apart from a locked steel door, is a six-inch wide vent in the ceiling, which Agent 47 uses to drop monkey chow into the room in order to lure in a Killer Gorilla, then a grenade to kill the gorilla.
  • In the Portal/My Little Pony: Friendship Is Magic crossover Better Living Through Science and Ponies, Chell uses some vents to get back inside the Enrichment Center. Justified in that her small pony body fits better.
  • In Blue Sky it's not exactly air vents, but climbing in the chaotic crawl spaces of the facility.
  • The absurdly spacious ones in Arkham are viciously lampshaded in the Batman fic Bruce Has A Problem; evidently they were originally dog runs put in by a director who thought dogs would have mental healing properties, abandoned when the director died in a dog-petting accident. They were then repurposed as vents by another director, who was looking to cut costs to fund a step pyramid he was building.
  • In the My Little Pony: Friendship Is Magic fanfic series Harpflank And Sweets — in the headquarters of the heroes, no less.
  • Used for infiltration in the Mass Effect fic Masses to Masses. Subverted when Ian's weight brings it down, resulting in Melanis lecturing him on how this trope doesn't work in real situations.
  • In the Stargate Universe fic Scribblings, Chloe and Rush both make use of a variant of this: Chloe turns it into a prison for Eli and Rush turns it into a nest.
  • In the Super Smash Bros. fic Smash Generation, this is how Midna went to see who was in the Mansion, and also how Pear, Riley, BJ and Popo evaded escape.
  • This is Eric's favorite method of travel in the Glee fanfic Spah Verse, both at Dalton and McKinley.
  • In the Persona/Super Smash Bros. crossover SSB The Return, Melody uses these to get around the school.
  • In the Mega Crossover Super Network Wars episode 27, some members of the Nueva Liga Filipina have to crawl through this in order to stop the poisons from being administered into the food of the VIPs at the 12th ASEAN Summit.
  • Occurs in Bubble Gum Crisis fanfic The Bubblegum Zone.
  • In the Harry Potter AU series The Darkness Series, Harry uses this when doing spy work at Riddle Manor in snake form.
  • The Chip 'n Dale Rescue Rangers fic Diamonds In The Desert is practically about this.
    • Also from the same series, Zipper gets into and out of the National Institute for Mental Health via air vents in Lost And Found, and the Rangers use the air-conditioning vents to get into Mr. Jacob's penthouse in Last Date.
  • The heroes use these to break into the base in the Jimmy Neutron fanfic The Other Side Of Tomorrow.
  • Occurs in the Star Wars Alternate Universe The Part to Be Played.
  • Part of the caper plans in the Undocumented Features fic Hellbringer and the After-School Special Mission Force #1: "The Bad Bank Caper" — as Lain Iwakura says, "Oh, good... I was -hoping- we'd be hitting all the cliches on this job."
  • This is how Carlos leaves the VILE base in the Where's Waldo/Carmen Sandiego crossover Where On Earth Spies. He's a small dog, so it works.
  • Used by the protagonists of Yu-Gi-Oh! Forever during the last part of the Dueltropolis arc, to sneak on board the ARK.
  • Calvin and Hobbes use this to infiltrate a base in Trouble Island.
  • Justified in Mass Effect Human Revolution: Ventilation passages in Krogan battle barges are huge because they're really meant for defenders to outmaneuver boarders.
  • Equestrylvania: In Book 2, after Rainbow Dash and Shatterstom are captured by Rose Blade, he has the former locked in a bathroom that's been converted into a holding cell/torture chamber; after getting free of her chains, she gets out of the room this way. Somewhat subverted, as it's a cramped fit, and Rainbow Dash is constantly worried that she's going to make noise and alert the Mooks below.
  • Sailor Moon: Legends of Lightstorm: In an attempt to bond with Sailor Mercury, Sailor Jupiter suggests that they get into a suspicious building by crawling in through the vents "like in the movies". Misunderstanding her intent, Mercury merely points out that the vents are probably too small for them to fit through.
  • Averted in The Keys Stand Alone: The Soft World. George talks about maybe navigating the air ducts to get to Mevaryat's basement room in the concert hall, but he isn't thrilled about the idea because he has no idea where the things go, and can't really navigate the larger world when he's something small anyway. Later, he finds out that the Tipaanese anticipated he might go in that way and set traps throughout the air ducts. Too bad for them he found a different way to get into the room.
  • Lampshaded in Child of the Storm, wherein Clint (and later, Bucky) like to crawl around in them to get into HYDRA bases (or in Clint's case, just because he likes crawling around in the Avengers Tower ones). Tony freaked out the first time. Now, being Tony, he still likes to pretend he has no idea of what's going on and send his robots to flush them out.
    • In the sequel, Bucky notes that they'd be amazed at how many HYDRA bases he's broken into, a point he's apparently previously made to Harry. Harry, however, prefers making his own doorways. Or using Doctor Strange as a chauffeur. As he loftily puts it, "One makes a statement, the other is economical.”
    • On a related note, it's become solid fanon in the Avengers fandom that Clint likes doing this. A lot.
  • Both played straight and deconstructed in the Batman fanfic "Of Friends and Foes." Robin and Kid Flash decide to sneak through air vents to eavesdrop on the JLA meeting for fun, and the size of the vents is explained away as being large enough for adults to come and work up there if a problem arises. However, it's noted that Robin still has to use his agility to get around, that it's pretty dirty, and that the boys have to keep their voices down to avoid being heard. Since one of the members has super-hearing and X-ray vision, one has Hyper-Awareness, and another is a telepath, it doesn't go too well anyway.
  • In Narbonic fanfic A Brief Moment of Culture, Artie hides from a mind-controlled Mell in the ventilation ducts. Justified because tiny little gerbil; it's made clear a human would have trouble fitting an arm in the ducts. And then subverted when Mell begins methodically smashing the ducts from one side to the other, which admittedly isn't something you can do with human-sized ones.
  • There are two instances in Pokémon Reset Bloodlines. Both of them are justified given that they involve relatively small Pokémon:
    • The first, Ash's Aipom sneaks aboard the vents in Hunter J's airship, opening the doors for Ash and the others to get through to escape.
    • The second, Ash's Snivy gets away from the Samurai by sneaking through the air vents of the battle club, and eventually seeing Ash and deciding to challenge him to see if he's the trainer she's looking for.
  • Mermaid Melody Pichi Pichi Duo: In chapter 8, the group uses one to sneak into the aquarium and find the missing Hanon. It ends up backfiring on them when they end up falling down a chute and landing heavily.
  • In All Guardsmen Party the Occurrence Border has plenty such passageways. When Sarge tries looking for similarly-size vents on a properly-built space station, he's told nobody would ever build vents large enough to crawl through. The only reason the Border has such vents is because it's a very stupid ship.
  • In Spice Girls AU Fic, Astral Journey: It's Complicated, after getting sectioned, Melanie does this "twice". Her second attempts ends in disaster, leading to getting injured for real.

    Film — Animation 
  • Subverted in Ed, Edd n Eddy's "Big Picture Show". Taking refuge in Eddy's Brother's room, the Eds try to get out the window. It's bricked in, as shown in a previous episode. ("My brother's a whiz at laying bricks.") While Edd tries to find another way out, he trips over a rug, revealing a heating duct. Eddy quickly pries open the grate, jumps in, and... more bricks. Then Ed finds the "In Case Of Movie Break Glass" case.
  • Lilo & Stitch: This is how Stitch escapes from the prisoner bay after breaking out of his cell. Justified because he's small and fast, and all the guards know he's there, they just couldn't shoot him in time.
  • The Secret of NIMH carries this over from the book it's based on. The rats make it out fine, however all but two of the mice are blown away to their deaths.
  • In Sky Blue, Shua flees Ecoban through the air vents after going through the Absurdly Spacious Sewer system.
  • Done by Trig in Starship Troopers: Invasion, where she has to strip out of her power armor to get into the vent. She also mentions that Bugspray would never fit when he wants to go with her.
  • Lampshaded near the start of Titan A.E. when Korso tells Cale to head for the vents. Cale responds sarcastically that no one would think to look for them there.
  • Toy Story and Toy Story 2. Naturally, ducts are much more convenient when you're eight inches tall.
  • Wallace & Gromit's The Wrong Trousers has air ducts to a museum big enough to stand in. They were realistically loud though, insofar as a pair of remote-controlled, vacuum-soled robotic trousers can be realistic.

  • Played straight in a book based on the Donkey Kong Country series, Donkey Kong was trying to get to a room containing an auto defense system in a building being built by Kremlings. As he tries to think of a way to get to the 8th floor without being seen, he hears guards coming, and goes into a nearby ventilation shaft. It's big enough to crawl through, and even has signs pointing him in the right direction.
  • Animorphs: Averted, since the one time this trope is used, Marco's in bug morph.
  • Duumvirate: The small kids who live in Northberg Educational Facility discover that they can go anywhere they want in the air vents. And the child-sized "secret" areas they lead to.
  • James Bond escapes confinement in Dr. No through some ductwork, but he soon discovers that it was a purposefully-built series of hazardous obstacles (poisonous spiders, extreme heat, etc.), complete with viewports for entertainment, intended as a deliberate obstacle course set up by Dr. No.
  • Justified in the sci-fi book Footfall, as the aliens are twice human size and deliberately put the captured humans to work cleaning the spacecraft's air ducts. Their prison cell also doesn't contain a handy air duct, forcing them to escape before using the ducts to evade.
  • In Illegal Aliens by Nick Pollotta and Phil Foglio, abducted humans on an alien ship hide in the air vents, because all the movies say that's what you do in that situation — only they aren't air vents; they're conduits for a horrifically deadly gas weapon, which the aliens are preparing to flood throughout the ship, because they can't locate the humans....
  • Something similar to the above happens in Artemis Fowl: The Arctic Incident. Artemis has to crawl through a duct filled with fuel for the building's plasma weapons. Before his helmet runs out of air. Without being able to see where he's going. Knowing full well that if anyone turns on the plasma cannons, he's toast. Once he gets out, he has to be sprayed with anti-radiation foam or he'll likely develop cancer.
  • Subverted in Christopher Brookmyre's One Fine Day in the Middle of the Night. After an earlier discussion of action movie tropes, one of the heroes spots the "Holy Grille" as the way out when they're held hostage. Unfortunately, he didn't reckon on the fact that crawling through metal ductwork is incredibly noisy, so everyone hears him as he tries to squeeze through.
  • Justified in Ender's Shadow. Bean uses the air ducts to explore and reconnoiter, but he can only do it because he designed a specialized workout to develop the muscles he needs to pull himself through at odd angles, and because he's really, ridiculously small. Eventually he grows too big to use the outflow vents anymore, but by then he is the commander of Rabbit Army and so has access to the larger inflow vents.
  • Works better in Mrs. Frisby and the Rats of NIMH than in most stories due to the escapees being rats. Well, right up until the system starts ventilating. This is one of the scenes that, legend has it, convinced Disney to pass it by as an animated adaptation. Something about having a large part of the party wiped out faster than the Redshirt Army, and without even an enemy to credit for it. They need help in opening the grilles, too.
  • Parodied in The Adventures of Samurai Cat, in which a cruise ship's air vents "... appear to have been designed for covert transportation." — "That would explain the moving walkways and vending machines."
  • Lyra crawls around in the dropped ceiling in Bolvangar in Northern Lights. Being a twelve-year-old girl, she's smaller and lighter than most Action Heroes, but she gets caught anyway, and almost transformed into a soulless abomination. She's only saved because the Big Bad had a special interest in her, and was present.
  • Used in the Honor Harrington spinoff Crown of Slaves, but used more realistically than many examples. Crawling around in them is murderously hard work, characters without detailed schematics get badly lost, and it proves almost impossible to remove a grille without the proper tools. Additionally, the ducts in question are on a space station and are deliberately designed to be large enough to crawl through since they double as maintenance access passages.
  • Referenced in Terry Pratchett's Only You Can Save Mankind:
    "I saw a film where there was an alien crawling around inside a spaceship's air ducts and it could come out wherever it liked," said Johnny reproachfully.
    "Doubtless it had a map," said the Captain.
  • Pratchett also pokes fun at the trope in Going Postal when, after a character fails to tunnel out of his jail cell, a guard remarks that the last guy in that cell — who happened to be unusually small and nimble — managed to squeeze through a tiny drain in the floor. Unfortunately, it didn't lead to the river like he thought.
    "He was really upset when we fished him out!"
  • Used and lampshaded in John C. Wright's Fugitives Of Chaos, Vanity—who has the power to find-slash-create hidden passages—finds an accessible air vent.
  • In Sandy Mitchell's Ciaphas Cain series:
    • In Cain's Last Stand, the air vents are exactly the place genestealers like to hide.
    • In other books, following a close call in Death or Glory, Cain makes a point of always acquiring the access codes to the maintenance conduits whenever he travels by ship. In one occasion where he didn't find the time to do so, Jurgen brought to his attention the fact that he was in a civilian ship, therefore its maintenance conduits didn't require access codes.
  • Used in the last two books of Timothy Zahn's Dragonback series; the (less-than-subtle) justification is that large air vents are actually standard design in capital ships, so that in the event of a hull breach emergency air supplies can be funneled to the compromised areas in large amounts, buying the occupants time to reach emergency air masks and so on. Although humans can't fit through them as it is, so it can almost be call a lampshading. Shontine/K'da ships are actually designed for the stealthy, compressible K'da to be able to move through in case of hostile takeover, and a human sourly remarks that he outgrew the ability to navigate even big ships' navigation ducts when he was seven. When a K'da takes to those vents for the first time she gets thoroughly lost; in a later escapade she's almost caught when her tail twitches in shock enough to thump a vent.
    • Played with in Zahn's Blackcollar novel The Backlash Mission, where the air intakes for a huge underground military base are large enough an adult human can walk through them, in order to accommodate the massive inflow needed and the filtering equipment to keep out poison gas attacks. Since even with the vents camoflaged, this is an insanely large security risk, the intakes are designed with a very large kill zone of automated defenses, which are described as completely undefeatable and possibly viable for centuries without maintenance. They actually were completely undefeatable. But with the base abandoned, there was no one to stop someone from spending months tunneling around the killbox.
  • Slightly altered in Harry Potter and the Chamber of Secrets, using the castle sewer-pipes for the monster to invade from — and for the heroes to find — the title chamber. Hogwarts Castle has got to have the most gigantic pipes ever seen... particularly for being built by wizards. Somewhat justified, in that the pipe leading to the chamber was designed to be a passageway to it, and thus capable of being accessed by the Heir of Slytherin. Likewise, a massive snake would have much more success than other monsters in navigating plumbing. Both had been planned by one of the people who helped create the Castle in the first place.
  • Comes up in several variations (breaking in, breaking out, air ducts, hanging ceilings...) in places in the Vorkosigan Saga by Lois McMaster Bujold, particularly the short story "Labyrinth" — where it involves problems like ducts forking or being blocked by grilles, and the others being only passable by the rather less than five-foot-tall main character, not his companions.
  • In Graham McNeill's Warhammer 40,000 novel Storm of Iron, this is how Hawke escapes a launching rocket and a Chaos Space Marine.
  • In the Women of the Otherworld short story "Chaotic" in the anthology Dates From Hell, Hope flees from a werewolf into an office, and finds herself in a dead end. She tries to escape through the air ducts, but she makes too much noise when moving and has to freeze when the werewolf enters the room. He finds her immediately. Later, after the pair has teamed up, they both move around through the air ducts, which are noisy, painful, cramped, and dusty. Still later, the bad guy enters a room looking for Hope, and while he's investigating the unscrewed air vent the good guys come out of their real hiding places and get the jump on him.
  • Averted in Robert A. Heinlein's Red Planet when one of the good guys proposes taking a vent grille off of a wall to get to the room on the other side. His friend points out that there will certainly be a similar grille on the other side, fastened by screws they won't be able to reach.
  • Isaac Asimov's Lucky Starr and the Oceans of Venus: Bigman volunteers to use an air vent in order to access a critical relay which, once disconnected, will prevent the Underwater City from drowning.
  • Deconstructed in Black Dogs. The ventilation in question is portrayed as tough, claustrophobic going in the dark, with Lyra, the protagonist, suffering several minor injuries, and a high chance of her falling and breaking her neck. Or breaking something else that renders her unable to escape, and dying slowly over several days.
  • Subverted in the final book of the Sten Series, by having the hero nearly get stuck in a claustrophobic moment.
  • Both played straight and subverted in John Ringo's Choosers of the Slain. They need to sneak into the secure facility of one of the bad guys, so (played straight) they pick the slimmest girl on the team, as the men on the team are too large especially wearing all their weapons. Subverted because they knew she would get stuck half-way down when the air vents narrowed, so her sole job was to get to that point and release a small robot (an R2-D2 toy they had picked up in a toy store and then modified to include surveillance and communications gear) which could go the rest of the way.
  • Used by Cammie and Macey in the third book of The Gallagher Girls series to get back into a building, though in this case it was still for escape rather than infiltration.
  • Subverted and lampshaded in Star Trek: Section 31: Abyss. After escaping her cell, Ezri Dax goes up into an air vent, which (contrary to what the holonovels of her youth would have her believe) is very dirty, dark, small and has creepy things living in it. (She is, however, successful in using the air vents to move throughout the base to important rooms.)
  • Subverted in A Certain Magical Index. In Volume 17 of the novels, Touma asks if he could use the ventilation ducts in the plane, but the flight attendant says that the ducts are too small. Touma admits that wasn't the plan and asks for some hot tea and coffee to pour down the duct, causing thermal expansion and make the terrorist on the other side think that there's someone crawling through the ducts, who lampshades that the act is just as suicidal as coming in through the actual entrance he was training his gun on. As a result, the terrorist gets some boiling hot tea to the face when he shoots the ducts, which also distracts him from Touma barrelling through the door and flinging a full pot of boiling coffee into his face.
  • Used in Age of Fire, where the two dragon siblings escape from a raid on their home cave by escaping through naturally formed air passageways.
  • In short story "In the Bone", the protagonist uses air ducts which were too small for his alien opponent but nonetheless navigable by the smaller human form. Some of the ducts are indeed too small for the human.
  • Justified in Witch & Wizard. In order to free innocent children being persecuted by the government for being witches and wizards from prison, the protagonist Wisty infiltrates one of the prisons through the air vents..... but she turns herself into a mouse first.
  • Played with in The Vampire Files. Jack can justifiably play this straight if he assumes a gaseous form (gas, after all, being what air vents are designed to let through). However, he's a bit claustrophobic and can't shake the feeling of being trapped while traversing a ten-inch-square conduit.
  • The Disreputable History of Frankie Landau Banks features the steam tunnel and pranking variant, as it is set at a school similar to MIT/Caltech mentioned above. It should be noted that this does not occur without consequences: one character gets a moderately-to-severe burn from the exposed pipes.
  • Somewhat altered in The 39 Clues: The Dead of Night, in which Phoenix Wizard and Reagan Holt try to escape the Vespers' prison by climbing up a dumbwaiter shaft. Justified, since the characters are children.
  • Averted and lampshaded in Sergey Lukyanenko's Competitors, when Valentin and Lena are confined to quarters in a Space Station. When Valentin suggests escaping via the air vents, Lena laughs that he watches too many movies and points out that the vents are barely a foot wide. Valentin's suggestion to set off the fire alarm has Lena point out that this would cause the quarters to be depressurized to contain the fire.
  • Under Alien Stars by Pamela F. Service has a crew from a hostile alien race take over a hotel, placing their prisoners on one floor. They remember to seal the edges of the air vents, but don't know or don't care about the garbage chutes descending past each floor.
  • In Michael Flynn's Spiral Arm novel In The Lion's Mouth, Bridget's first guess is such an escape before she deduces that in fact Ravn hid Invisibility Cloaks in the ventilation system, and then escaped, invisible, with her companion as soon as the door opened.
  • The Rings of Saturn: The space pirate base has an extensive air ventilation system, extensive enough that a Mad Scientist was able to live alongside the inhabitants and move around the base for years without their knowledge.
  • Sixty Eight Rooms: The two kids manage to fit easily in the Museum's air vents as they have been shrunk down to five inches. Getting up to the vents was much harder.
  • Cannon Fodder: Kelsey says she escaped from Black Jack's base in this way, but we never see it happen.
  • Attempted by Rolas in "Captive of the Red Vixen", after he figures out that his Shock Collar is only tied to the door to his cell, but he finds a note from his captor and a trap waiting for him at the grille above the lifeboats.
  • Averted in Get Blank when Blank uses a false ceiling, rather than any kind of duct, to get around.
  • Occurs in Heaven's Queen, third book of the Paradox Trilogy. When Brenton is helping Devi infiltrate Dark Star Station, he shows her a passage to crawl through and she assumes that it's an air vent. Brenton tells her that the people who built the station weren't that stupid; the passage is a power conduit, and usually filled with plasma heated to thousands of degrees. They're only able to use it as a passage because of a power outage.
  • In Symbiont, second book of the Parasitology series, Sally tries escaping captivity in a mall this way. She manages to make her way through the system only to find her guard Ronnie patiently waiting for her at the end; once he saw that she'd entered the vent, he was able to casually stroll over to the exit grating while she slowly crawled her way through the duct.
  • In the Dred Chronicles, the Prison Ship Perdition has enough of these that Tam, Dred's advisor, can use them to eavesdrop on rival gangs. This allows him to provide Dred with useful intelligence, which both protects the gang and encourages Dred to rely on him.
  • Andre Norton's Uncharted Stars. While on the pirate space station Waystar, Murdoc Jern's companion Eet enters the station's air ducts to do some snooping.
  • In Tales of Dunk and Egg, it's revealed at the end that Bloodraven had a few dwarfs sneak in through the privy to steal the dragon egg. Justified, seeing as they're dwarfs.
  • In Wander, Wander and Dagger use the airvents to escape from a nest of smilers set up in an abandoned prison.
  • The main characters use this method of travel at one point in H.I.V.E.. The trope is played a bit more realistically than usual: the vents are not well-lit, the characters are concerned about the noise they're making, their route has some difficult paths and "obstacles", and there's some mention of the effect that crawling along a cramped space would have. When entering the vents, they have to use a screwdriver to remove the grille. The only reason they don't get lost is because of Otto's uncanny ability to remember their route. However, they oddly don't have any difficulty removing the exit grille (and due to the exit's location, there was no way they could have checked it beforehand). There's also no excuse for the lack of security cameras in the air vents, given they're big enough to crawl through.
  • The Boy Who Knew Too Much by Roderic Jeffries. A youth breaks into an abandoned factory on a bet and finds himself pursued by masked thugs. The detective assigned to the case is reluctant to believe him, but then sees the marks where the kid dived down a chute and notes that he must have been pretty scared to have jumped in there without knowing where it came out.
  • Subverted in The Many Lives Of Stephen Leeds. Ngozi proposes this as a way of getting into a building with security cameras — because she's seen it on TV — but J.C., who is a military expert (sort of), lists several reasons why it's impossible. They do find a creative use for an air vent, but it only involves hiding a mobile phone inside.

    Tabletop Games 
  • Dune: Chronicles of the Imperium main rules, adventure "Instrument of Kanly". The agents of House D'murjzin enter and exit the 35th floor of the Adici Enterprises corporate headquarters through an air vent.
  • Necromunda has this as a territory which gives the option of starting behind your opponent. Jutified as Imperial hive cities can have ventilation shafts kilometers wide.
  • Traveller
    • FASA's Classic supplement Action Aboard: Adventures on the King Richard. A paragraph details how the air ducts can be used to move around the ship.
    • Challenge magazine #32 adventure "A World On Its Own''. One way for the PCs to get into the starport is to go through the service ducts for air circulation and electronics lines. The only problems are that most of the ducts are barely large enough for human beings and the chance of getting lost.
  • Paranoia 1E supplement Acute Paranoia, adventure "Outland-ISH". When the Troubleshooters are trying to get to ISH sector their High Programmer opponent tries to stop them by putting a convoy of vehicles across their path. They can get around this by finding and using an air vent passage.
  • Chaosium's ElfQuest RPG main rules, adventure "The Dying River". The elf PCs can get inside the troll tunnels by finding one of the airholes that the trolls use as a ventilation system.
  • Encounter Critical supplement Asteroid 1618. Small creatures can pass through The Vanishing Pyramid's ventilation system, but they must roll well or either get lost and exit in the wrong room or have to fight off packs of Raider Rats. If they survive they can scout out the contents of 2-8 rooms before having to roll again.
  • Buck Rogers XXV (in the 25th Century) adventure XXVCA3 Deimos Mandate. When the pirates attack the RAM meeting, Mortimer tells the PCs to enter two air vent ducts and move around using them in order to ambush the pirates.
  • The Widow's Walk expansion set for Betrayal at House on the Hill includes room cards which have dumbwaiters inside them; using one costs a movement space, but it allows you to go directly to the floor landing above or beneath you.
  • Shadowrun supplement State of the Art 2063. HVAC (Heating, Ventilation and Air Conditioning) systems have ductwork that can be used by shadowrunners to infiltrate corporate buildings. Knight Errant Security recommends that the ducts be made too small to allow entry by intruders.

    Visual Novels 
  • Apollo Justice: Ace Attorney:
    • The only reason the title character's client in the third case is accused of the murder is that it's a Locked Room Mystery and he's the only one small enough to fit through the vents (where they found his fingerprints). He did escape the crime scene through the vents, but didn't commit the murder.
    • Also, the air vents were used by Lamiroir to get from one side the stage to the other quickly for her part in the magic act in the middle of her song. They are stated to be large enough for her to walk, albeit hunched over and there was staff waiting at either end to help her.
    • Phoenix Wright: Ace Attorney – Dual Destinies gives us a variant - Apollo suggests that someone walked through an air vent, but investigating the thing later shows that while it was possible, it was certainly not done and he has to come up with another defense.

  • Angels 2200: Loser uses one when they attempt to "rescue" Quetz
  • Subverted in Freefall, when Sam finds out the hard way that the air ducts on his ship are not quite big enough for him to hide in. He might have succeeded if he had ditched his encounter suit.
  • Justified in Schlock Mercenary, as Schlock is a carbosilicate amorph — he can squeeze through air vents no matter how small they are — well, except for his eyes (standard Sphere Eyes) and his plasgun (big).
  • Justified in Gunnerkrigg Court, as the Enigmaron fortress that Antimony infiltrates is a simulation.
  • Used in a Help Desk comic, the reasoning behind such large vents is questioned and explained as Contractual Genre Blindness in the next strip.
  • Casey and Andy
    • Subverted: Casey sneaks in through the airvents, but is met by the Mime Assassin inside the air vents, as the villain had been expecting the plan.
    • The C&A villain Lord Milligan follows the Path of the Villain as a religion and deliberately follows every cliche. Including having giant air ducts.
    • They try the air vent route multiple times, and the mime-assassin is in there every single time. Including the last time, when they were finally expecting it, and had someone outside the vent stab through it.
  • Wonderfully subverted in a strip of Ctrl+Alt+Del, given that it LEADS TO THE DEATH OF THE MAIN CHARACTER! Thus ending this Choose Your Own Adventure storyline.
  • Nepeta is ordered by Equius to do this in Homestuck.
    • Later on, Gamzee also does this to creep on others.
  • Subverted in Questionable Content when Raven attempts to enter Coffee of Doom through the airvent and gets stuck. She's not the sharpest of minds, though.
    • And it's not like she was trying to rob the place or anything. She and another character, both recently hired there, show up to their opening shift and realize that neither of them have a key, on a day their boss is taking some personal time. Cue Raven's exceedingly well-crafted plan to get in so they could open the shop without bothering said boss.
  • In Ronin Galaxy, Taylor and Rin use the floor's ventilation ducts to escape the brothel. They're both relatively small people, so it may be justified.
  • Sluggy Freelance
    • Used in a strip to sneak into Aylee's office. Justified since Bun-Bun, a mini-lop rabbit is the only one who can make it through.
    • Used again in another strip. Also justified, since it's done by Rudolph the Reindeer, who has picked up all the tricks Santa uses for shimmying up and down chimneys.
  • Banished: To escape from the Boscis base, Rak and Timbo follow a Mammazon out this way.
  • Charby the Vampirate: When Tony was cornered near a door he couldn't use inside the hunters' headquarters (since as an alp he can only leave the building the same way he entered it) he took possession of a rat monster to take the vents to where he needed to go.
  • Justified in Curvy when used by a native of Candy World who is actually a liquorice-based organism: she can squeeze into places a normal human wouldn't be able to. In fact, in the immediately previous page she's seen squeezing through the bars of a prison cell.
  • Averted in Dead Winter. Lou's plan for getting into the store for supplies involves this method, but Monday objects on the grounds that he won't fit. Apparently he's tried before.
  • In Drowtales, the air vents are too small for an adult Drow. But for a child...
  • Trigger from Far Out There is very good at these.
  • In Girl Genius Castle Wulfenbach has a number of truly enormous grated vents which Gil uses to take Tarvek, Bang and Vole to one of his hidden labs when Tarvek figures out Gil's father has been wasped and is somewhere on the ship covertly giving orders. Gil notes that Tarvek really needs to escape since even if he's wrong about what has happened to the Baron the Baron would likely have him shot on sight.
  • In El Goonish Shive, Noah uses air vents in the process of hunting a magical creature, and the trope is discussed in the commentary. And Noah also does it to get around school! Raven has to shout at him to use the door.
  • In The Motley Two, the spaceship "Hiroja" has vents big enough that the characters can sneak around the entire ship with impunity. Perria Makara, who snuck aboard undetected, even sleeps quite comfortably in the vents (near the heating unit).
  • Metroid: Third Derivative: Samus with the Morph Ball up until Phazon corruption damaged her Varia Suit and required emergency repairs destroying the Morph Ball in the process.
  • Nerf NOW!! on air ducts in games vs. reality. No inescapable death trap is complete without one!
  • Lampshaded by the Deadpan Snarker in the improvisational comic The Omega Key on this page, where he finds it suspiciously convenient that he (a 6'10" man) can fit in an air duct. (He was right, as the destination turned out to be a trap.)
  • In Outsider, Jardin lampshades the lack of handy vents.
  • Malum Industries of Permanent Inc have air ducts built intentionally wide enough to crawl through.
  • While it would appear to be justified in Star Mares due to ponies being smaller than humans (while the scale of the ships is unchanged from the originals, to better accommodate the larger ponies and pegasi), ventilation shafts are still explicitly stated to be designed for air, not ponies, and are depicted as being cramped and dirty. One character also later complains of the lack of security measures inside maintenance tunnels (which she is in the process of sneaking through).
  • In The Inexplicable Adventures of Bob!, this is how a quartet of time-displaced ninjas escape from the museum where they have awoken.
  • Played with in Bob and George, where Kalinka and Ran try using air ducts to sneak into Wily's newest lair. Ran dies twice, trapping Kalinka in the duct, and necessitating that Blues show up to help her out of there.

    Web Original 
  • Used to escape a dead-end in Survival of the Fittest by John Sheppard, Vera Lang and Kyrie Joseph, as killer Harry Tsai was hot on their heels and it was the only way out of the building they had run inside.
  • Shelton and Ridgeway successfully do this in Darwin's Soldiers: Schrodinger's Prisoners. It's also subverted in the third RP when Hans suggests this as a way to get into Pelvanida and James points out how that wouldn't work.
  • Tech Infantry has a sequence where a space station is captured by rebels, and they lock Xinjao O'Reilly, the chief engineer on one of the space docks, in a tool storage closet with his engineering crew. They hang a lampshade on what a stupid move this is, grab a bunch of tools, and escape into the maintenance passageways between bulkheads. They make life very difficult for the rebels controlling the station for a while.
  • Played straight in Magical Girl Hunters when sneaking into the Mashihaishi Ultra building. The confusing layout is lampshaded with Yoi asking directions of other people traveling through the same vent system.
  • Mercs has this done by Varisa and Creed to sneak around the ship during the "Hijack" episode. At one point, one of the mooks tracks Varisa by the banging noises in the ductwork and ambushes her when she comes out.
  • Duct Hunt, a parody of the Metal Gear series made by Rocket Jump, deconstructs almost every aspect of this trope, including the way some players tend to use it in Metal Gear.
  • Kai tries to use one of these in the first episode of the Chronicles of Syntax to get out of the school. It doesn't quite work out how he expected.
    Kai: Okay, this thing is definitely getting smaller. I might just hyperventilate myself into a coma down here. They'll find me years later, turning to dust in the fetal position. Can I even get into the fetal position? I don't care. Just keep moving. Just keep moving forward...
  • SCP Foundation, Characters/SCPFoundation
    • SCP-932 ("Night Feeder"). During the containment breach described in Incident Report 932-02 SCP-932-06 escaped, apparently by somehow getting into Site-09's air ducts. While in the air ducts it reproduced, creating SCP-932-07 and SCP-932-08.
    • SCP-1341 ("JUNGLE IN A JAR"). Doctor Boyd, the lead researcher on SCP-1341, wrote an account on the outbreak that led to the site being overrun with jungle plants. The last entry is his statement that he's going to commit suicide.
    • SCP-2978 ("Motherburg"). The SCP-2978-B entities being held in Site 17 change a wireless modem into a flying vehicle and start to explore. Three minutes later the vehicle enters a ventilation duct and visual contact with the vehicle is lost.
  • Episode 1 of The Orbiting Human Circus (of the Air) opens with protagonist Julian the Janitor's personal Interactive Narrator describing Julian having managed to get backstage by holing up in a heating duct, preparing to sneak into the eponymous radio show's ballroom studio for the third time in a week.

    Western Animation 
  • Archer is fond of this. Somewhat surprisingly, it's always played straight.
  • Subverted in Avatar: The Last Airbender. The Gaang was stuck in a room and the only exits were air tubes, so they tried to get Momo through it. However, Momo ate too much, and couldn't fit. Momo later did crawl through some tubes in Roku's Temple, though it wasn't actually an "escape".
  • The Batman
    • Justified when Ragdoll uses it; he is the most flexible person to have ever lived, and the air vent only needs to be big enough for his head to fit in, as many air vents are in Real Life.
    • Also played straight in the episode "The Butler Did It" when Alfred has to escape from a room to warn Bruce. He pronounces it "quite a sticky wicket."
    • And again in "Thunder" by Batgirl several times to escape from Zeus' henchmen on his airship, and to tinker with said ship's power supply.
  • Batman: The Animated Series
  • Parodied and subverted in Batman Beyond: The protagonist enters a vent large enough to walk in, but the subsequent sections keep getting smaller and smaller.
  • Batman: The Brave and the Bold
    • Subverted and played with: Batman is infiltrating a parallel Earth, disguised as his evil counterpart Owlman. He's allied himself with Red Hood, the heroic counterpart of the Joker, who is being tortured by Silver Cyclone, the evil version of Red Tornado. Batman sneaks through the air vents to free Red Hood and escape after his cover is blown by the evil Atom. This might have worked... except Silver Cyclone apparently had a tracking device or something on Batman, because the moment he realizes that Red Hood has been in contact with someone, he remembers that Owlman has been acting strangely and his computer immediately tells him Batman's location, in the air vents, proving that he's a spy. Silver Cyclone then powers up the fan to slice "Owlman" to pieces. This is the goddamn Batman we're talking about, so he blows up the fan. But still, the escape turned out to not be the best idea.
    • Averted in "Menace of the Conqueror Cavemen!", as the air vents are cramped. They also shake and make a good deal of noise when Batman and Booster crawl through them. Fortunately Kru'll isn't paying much attention.
  • Ben 10 did this a couple times, though it's Justified by the fact that, both times, Ben was transformed into an alien form that was five inches tall and gave him greatly enhanced brainpower.
  • Birdman episode "The Quake Threat". When Birdman is trapped in an Elaborate Underground Base, Avenger the eagle breaks in through an air vent to save him.
  • Lampshaded and subverted in an episode of Buzz Lightyear of Star Command, when Emperor Zurg chews out the designer of his latest evil lair for making the air ducts big enough for heroes to fit through.
  • Chip 'n Dale Rescue Rangers uses this in a few episodes. Then again, the use is probably justified as the Rescue Rangers themselves are only around 10 cm tall.
  • Code Lyoko:
    • In the episode "End of Take", Ulrich and Sissi crawl through an air duct in the factory after being pursued by a prop alien. They don't get too far.
    • In the episode "Canine Conundrum", Yumi and Ulrich escapes from the Gymnasium (besieged by robot dogs) this way. Although there is a joke, previously, about the adult teacher, Jim, being too fat to follow them.
  • Danny Phantom: In the episode "Doctor's Disorders", the only way to save the hero so he can stop the villain is to go in by the way of an air vent.
  • The Deep: In "Lonesome Jim", Ant and Fontaine crawl through the air vents on Evil Poacher Conger's submersible base. Fontaine comments on how overrated air vents are as a means of passage.
  • The Dennis the Menace cartoon does this in one episode when he's trying to flee with Gnasher from a large mobile mall that has arrived in Beanotown and hypnotizing everyone into buying useless junk. Whilst crawling, they find the office of the mad scientist behind the plot, and instead of escaping Dennis decides to bring him down instead.
  • In an episode of Detention Miss Kisskilya gets the gang in shape by locking up the school to lock them in the classroom, so they plot an escape through the air vent.
  • This is Lee's usual mode of transportation around the school in Detentionaire. He started doing it to keep out of Principal Barrage's way and off the security cameras, and by now has spent enough time in the vents to know his way around very well and be able to get from one end of the school to the other as fast by vent as he would using the hallways. Other characters have used air vents as well, though not to the same extent as the protagonist. The air vents of A. Nigma High also happen to house a red snake/lizard/dragon monster called a Tazelwurm, who could kill you in a second and is also the school mascot. He turns out to not be as dangerous as he looks, though.
  • Dogstar: After Boombah locks the crew of the Valiant in their cabins in "Robbie", Simone has to crawl through the vents to reach the bridge.
  • An earlier episode of Ed, Edd n Eddy about the trio trying to watch a monster movie marathon had them use this to get out of the bathroom and to the TV around Rolf(who was talking their ears off with another outlandish story). They do briefly get stuck, but Ed is able to push them out with relative ease.
  • In the season 1 finale of Exo Squad, after taking their attempt to use Phaeton as a hostage fails, Able Squad escapes the Brood Chamber via the air ducts. Typhonus responds by sending troops into the tubes; why the tubes were made big enough for Neosapiens to walk around in isn't explained. Then he reroutes the ventilation so the tubes are flooded with poisonous "volcanic gas". Exactly why someone would build a ventilation system that allows that isn't explained either.
  • Peter and Brian do this in an episode of Family Guy, complete with a Shout-Out to Die Hard. They don't make it all the way in stealthily, though; Peter's large girth causes the vent to give out and dump them right in the middle of the prom.
  • Fantastic Voyage Animated Adaptation
    • Episode "Revenge of the Spy". The protagonists use this technique to move around inside the enemy building, but it's justified because they're miniaturized to tiny size.
    • Episode "The Perfect Crime". The criminals in their miniaturized helicopter use an air vent to attempt to escape the U.S. Mint building at the same time that the Voyager enters the building using another vent. The two flying craft meet inside the vent and do battle.
  • In the made-for-TV Felix the Cat cartoon "A Museum, The Professor and Rock Bottom", Rock Bottom tries to escape from Felix in the art museum by using this tactic. It doesn't work, because not only can Felix clearly hear him travelling through the air conditioning vent, the vent is so small that Felix can see Rock's burly form squeezing its way through. He forces Rock out by setting the temperature so low, that Rock slides out the vent, frozen solid in an ice cube.
  • Futurama:
    • Subverted: Fry and Bender try to escape from a brig through a steam pipe vent. Unfortunately, the steam pipe is full of steam. At least they got a good sauna out of it.
    • Lampshaded in Bender's Big Score. While trying to destroy a "Death Star", Al Gore's head in a jar flies a through an air vent actually labeled "Achilles' Vent", lasers a-blasting, successfully destroying it.
    • In Bender's Game, Fry and the other travel around Mom's factory through a tube that sends chickens to the enslaved Nibblonians. It works, but they have to shove their way through a lot of chickens.
  • Gravity Falls. In the episode "The Inconveniencing", Dipper uses the HVAC vents to get into the abandoned Dusk 2 Dawn convenience store.
  • Helga from Hey Arnold! used this method to sneak into the boarding house in "Helga Blabs it All".
  • Given her size, Jade from Jackie Chan Adventures utilizes these at times to get around places when no one else can. The episode "The Day of the Dragon" feature both her and the Dark Hand using the air vents to escape Section 13.
  • In a Jem episode, Jem, Aja, and Shana do this to escape a locked room.
  • Subverted in the Jimmy Two-Shoes episode "Jimmy in the Big House", when Jimmy and Beezy tries to get out of prison by going through air vents. Suddenly, a screen pops out and it's a video message from Heloise who lets them know that they have made it far in escaping but in her prison, there is NO ESCAPE! As a result, they are blown out of the air vents by the fans at high speed and back to where they were. In this case, it's probably justified since Heloise probably made the vents that big just to crush prisoner's hopes for escaping.
  • Jonny Quest episode "Mystery of the Lizard Men". Jonny crawls though an air duct to escape from the title opponents.
  • Justice League. In "Eclipse", Flash is being chased through the Watchtower by a possessed Superman. He does an Air Vent Escape but leaves a door open to the corridor outside. Naturally Superman assumes Flash would rely on his Super Speed rather than crawl slowly through the air ducts.
  • Kim Possible and Ron infiltrated this way in The Movie. They do it quite a lot during the series.
  • Zadavia stages one on Deuce's ship during the Loonatics Unleashed episode "In Search of Tweetums, Part II".
  • In an episode of Max Steel, the only entrance to a highly-secured building is through the air vents. The only way in is by careful timing to avoid being sliced by a giant fan; the vents end two-thirds of the way up the wall in a room where the floor is littered with explosive devices, and not only do the air vents have cameras, they're also equipped with flamethrowers the big bad of the episode can activate at will.
  • The Penguins of Madagascar: Penguins try this in "Officer X factor", but X switches the vent on and they fall down the passageway.
  • Played straight in The Problem Solverz episode "Badcat", when the solverz travel through a vent to reach Bad Cat's lair on the top floor of his casino.
  • Recess: T.J. often uses this route to break himself and occasionally others out of detention.
  • Robot Chicken lampshaded this in an Iron Man spoof. Two Mooks guarding The Mandarin's lair are able to instantly determine that the deafening banging and screeching noises they hear are from Iron Man trying to sneak through the air ducts.
  • Sam and Max, and Sam's granny Ruth, try to reach the prison warden this way in the Sam & Max: Freelance Police episode "Christmas, Bloody Christmas" — only, instead of the air vent, they go through the prison's water duct, and end up in the shower room.
  • The Simpsons
    • Parodied in the 100th episode. Santa's Little Helper gets into the school ventilation shafts, and only a greased Scotsman can catch him....
      Groundskeeper Willie: Lunchlady Doris... 'ave ye got any grease?
      Lunchlady Doris: Yes. Yes we do.
      Groundskeeper Willie: [tears off his clothes] Then grease me up, woman!
      Lunchlady Doris: ... Okee-dokee.
      Groundskeeper Willie: There's nary an animal that can outrun a GREASED SCOTSMAN!
    • This is how Homer spies on Mr. Burns meeting with terrorists, and would be caught if it wasn't Played for Laughs:
      Homer: [scribbling on pad] I love spying.
      [terrorist picks up a bar of uranium; radioactive gas boils off the surface of the rod]
      Burns: Don't worry about those fumes. They'll be sucked into that air vent.
      [Homer moans from fumes, drops pad out of vent and onto the floor]
      Burns: This place is falling apart. [walks over, picks up pad and shoves it back into the vent]
    • In one of Homer's daydreams where terrorists take over the plant, Homer jumps from a standing position into a vent on the ceiling, then comes out in Burns' office to beat the terrorists up.
    • In "Lard of the Dance", Bart and Homer crawl through the vents while trying to steal grease from the school cafeteria, followed by an angry Groundskeeper Willie. The passageway is wide enough that Homer and Willie can fight inside of it.
  • In Sonic Sat AM, most episodes that contain Robotropolis have the main characters in an air duct at LEAST once. Robotropolis is perhaps Air Duct Central, essentially one giant factory bathing in its own heated (polluted) air. Lots of cool (polluted) air has to be moved around to keep the place from overheating somehow. By the way, Robotnik hates this trope:
    Robotnik: Tell me, Snively, how did the hedgehog get past all my security?
    Snively: Through an air duct, Dr. Robotnik.
    Robotnik: An air duct? Then SEAL IT OFF!!
  • Space Ghost episode "The Space Piranhas". Jan and Jace infiltrate an enemy base using the ventilation system. Lampshaded when the Big Bad says "As usual, the intruders have taken refuge in the ventilating system".
  • Spider-Man: The Animated Series constantly had Spidey doing this. During the Venom arc, after Peter finds the symbiote and experiences drastic changes to his personality, he considers but chafes at using the trope, saying "That's the old Spidey talking." He instead goes for the direct approach: kicking the steel door down and barging into Kingpin's meeting.
  • SpongeBob SquarePants, "Truth or Square": after getting locked inside the Krusty Krab freezer, the gang makes their way out through the restaurant's labyrinthian ventilation system.
  • Star Wars: The Clone Wars:
    • "Rookies": During the initial commando droid attack on the Rishi Moon outpost, the titular rookie clones escape from the base via an airvent. The vent is used a second time as an exit when the clones are planning to blow up the base to cut off the hardwired all-clear signal and destroy the Separatist reinforcements.
    • "Duel of the Droids": Ahsoka escapes General Grievous this way.
    • "Cloak of Darkness": Ventress used the airvents to infiltrate and sabotage a Jedi Cruiser unnoticed.
    • "Holocron Heist": Cad Bane infiltrated the Jedi Temple through the airvents. Doubles as Absurdly Spacious Sewer.
    • "Brain Invaders": Ahsoka Tano and Barriss Offee escape from mind-controlled clone troopers by jumping into the air vents. Later in the episode, Ahsoka uses the same vents to travel to the coolant control room and the bridge while she's running from Barriss.
    • "Assassin": Aurra Sing used these to attempt to assassinate Padmé.
    • Subverted and lampshaded in "The Citadel". With the entry point the Jedi wanted to use blocked, Anakin and Obi-Wan muse how to get in, and Ahsoka points on the ventilation hatch. Anakin argues that they're too small to gain access, but in response Ahsoka points out, that they might be too small for Anakin, Obi-Wan and the clones, but she might be able to squeeze through — which she is, although barely. In the next episode Obi-Wan's entire team tries to escape the Citadel in absurdly spacious airvents. However these had lethally effective security doors, and the warden at least had enough common sense to send at least one drone in the airvents.
    • In "A Test of Strength", Hondo Ohnaka proves he is smart by immediately recognizing the trick and having smoke bombs dropped into the vents to flush out the occupants.
    • The second episode of the unfinished Utapau arc had Anakin and Obi-Wan try to escape from a group of armed weapons dealers by crawling through their ship's ventilation system. However, not only do the arms dealers simply shoot into the vents, the vents are so cramped that the Jedi have to use the Force to move each other around to avoid getting shot.
      Obi-Wan Kenobi: Brilliant Idea. This is a much narrower space. No room to maneuver, we'll be shot for sure.
      Anakin Skywalker: Sorry. I thought it would be a good place to hide.
      Obi-Wan Kenobi: It's never a good place to hide. We're always in the ventilation duct, every ship we go in.
  • Star Wars Rebels: In the first two seasons, Ezra Bridger spends a lot of time crawling around in ducts. The fact that he's a scrawny, underfed teenager helps a great deal. By Season 3 he's had a growth spurt, so he can't do this anymore. Oddly enough, serves as a Call-Back in the series finale, when Ezra decides to sacrifice himself he escapes the room through the air ducts, even noting "one last time" as he does.
  • Teen Titans:
    • Exception; Titans Tower's quarantine lock-down system apparently does seal off openings to the air ducts, as seen in the episode "Haunted". (Robin got into the vents anyway....)
    • Subverted in the same series: Cyborg is attempting an Air Vent Infiltration in the episode "Wavelength" when the walls roll up and the thing rotates, dumping him into an arena and a battle with Bumblebee which he very nearly loses. He should've thought twice about even coming across a vent big enough for his 6-foot, 200-pound chassis.
  • This is a favorite route of the girls in Totally Spies! for breaking in, clearly thanks to Male Gaze. Also done in the spinoff The Amazing Spiez though vaguely more realistically due to the characters being 13 (Lee), 12 (Marc and Megan) and 11 (Tony). Even more plausibly the character seen doing this the most is Tony who, due to his young age, would realistically fit.
  • Transformers
    • The Transformers episode "The Ultimate Doom, Part 2" introduced ventilation ducts large enough for Transformers to stand inside. Spike, Bumblebee & Brawn go through a ventilation shaft that takes them to Decepticon HQ. They're on Cybertron, where everything is of the same scale as Transformers are to humans, but why would they need air anyway?
    • And pulled again in Transformers Animated, episode "Decepticon Air". Optimus Prime crawls through the ducts (it seems to be a squeeze, letting him homage Die Hard as well) of a spaceship — maybe the air circulates to keep the energon from heating up and getting unstable? He does use it as a makeshift bomb, after all.
    • Beast Wars: Cheetor goes through the ventilation shafts of the Predacon ship after having been accidentally transported to The Darksyde in "Equal Measures".
  • The strangely clean air ducts of the SHIELD Helicarrier are lampshaded in the Ultimate Spider-Man episode "For Your Eye Only" which, as a spy movie parody with nods to Die Hard, has Spidey using air ducts rather frequently.
  • Defied in Wolverine and the X-Men: Wolverine and Gambit are trying to break into a secret lab to steal back a power inhibitor collar, and Wolverine suggests taking advantage of this trope. Gambit counters with: "Heh, only in the world of cinema. In real life, they never hold." It certainly doesn't help that Wolverine's metal skeleton makes him about three times as heavy as a normal person.
  • X-Men: Evolution
    • Subverted, with the vent being only a few inches long, big enough for people to climb into, having a ladder inside, and Blob gets stuck. However, it also has a large amount of security lids which Cyke was able to close to keep Mystique from escaping.
    • Played with in another episode. When the group is testing out the security of the mansion, Wolverine is able to go to many parts of the mansion through the vents, and suggests something be done about them.
  • Young Justice:
    • In "Homefront" - the "Die Hard" on an X episode - Robin and Artemis spend a lot of time trying to avoid the Reds by crawling through the ducts; with varying degrees of success.
    • In Season 2, a group of female team members do this in a bad guy's lair. The only one it makes sense for is Bumblebee who uses her shrinking powers to fit. On a more realistic note, all of the full-size heroines are shown having some difficulty maneuvering in the tight space.

    Real Life 
  • To this day, criminals will attempt this trope at any number of buildings where they can find a suitable opening. The difficulty they will encounter is that ducts don't stay the same size or shape all that often. The added difficulty of straight up-and-down ducts will see many criminals slipping and falling to become wedged or even killed by the fall. Even worse for some criminals is they may attempt this on holidays or weekends to avoid being heard clambering through the ventilation. When they become trapped, they must wait days without food or water in extremely uncomfortable positions for somebody to discover them. Given that some buildings are closed for months at a time (if not permanently), it's not surprising that several unlucky burglars have ended up starving to death before being found.
  • In Real Life, small animals tend to be more successful at this trope than humans (they're small enough to get inside easily, they're light enough that the ducts can support their weight and they don't make as thunderous a noise while they move around). Depending on the animal, they can still be very loud as claws or nails make a racket running on metal.
  • During and around The Dung Ages, a popular way to infiltrate a stronghold was to climb through the privy chute. This had varying outcomes; either they made it, and incidentally killed Edmund II by puncturing his arse, or they got stuck and died in there, or they suffocated and then died in there. After such sieges, those chutes had to be cleaned elaborately and swept through because of all the stuck-up cadavers.
    • This is how the castle of Chateau Gaillard was defeated when the new owner of the castle, John, (yes that Prince John brother of Richard the Lionhearted) added a new latrine to the fortress near the front giving the once impregnable castle a massive new entrance to be exploited (the new chute was 2 meters square at the base and was outside the castle's moat). The original castle only having small chutes positioned where entering them would be foolhardy. All because John was too lazy to use the latrine at the middle or back of the castle.
    • According to some sources, this was how Finnish Cudgel War leader Jaakko Ilkka escaped from his imprisonment in the Turku Castle.
  • This was attempted in 1994 by Cleveland Indians pitcher Jason Grimsley to try to switch out teammate Albert Belle's corked bat before the umpire could find out he was cheating. Going through 10 feet of ducts and a false ceiling, he might have even gotten away with it if he hadn't replaced it with an autographed bat.
  • Defied in Sensitive Compartmented Information Facilities, a.k.a. SCIFs, where top-secret intelligence information is handled in the United States have a list of regulations on construction of air vents, including grates to prevent entry and deliberate metal disconnects to avoid sound transfer.
  • Successfully done by serial killer Ted Bundy. While in prison awaiting trial on one of many murders he was suspected in, he climbed through the roof of his cell (he had dieted and lost enough weight to make this possible), crawled across the floorboards into the adjoining warden's apartment (the warden and his wife were out at a New Year's Eve party), and simply walked out of the apartment into freedom. He was caught several weeks later, but not before adding several more victims to his list.
  • When Kingsley Ofosu and 8 other Ghanians stowed away on a Europe-bound cargo ship, he escaped from the ship's murderous crew (the other stowaways were not so lucky), by shimmying up one of these.
  • Quawntay Adams managed to escape from a jail by going into the subceiling and out through a vent. It was harder than it sounds; after getting a hacksaw blade to get through the ceiling, he had to both time the guards, evade the cameras-including the one in his cell-and get to his accomplice outside. His grand total of freedom? Seven hours.
  • On a G4 special one of the famed Bioware doctors mentioned how as a child his teacher locked him in the closet for misbehaving, he climbed from the closet into the drop ceiling Breakfast Club style. After crawling back into his classroom he positioned himself over where the teacher was standing and dropped a lugie on them.
  • Attempted unsuccessfully by Jamie Minor. She tried sneaking into her workplace by the air ducts but got trapped, and was found dead over a month later.
  • Russian President Boris Yeltsin was thought to have done this once during a stay in Washington D.C. in order to evade security (the security aimed at protecting him) so that he could go out for a night on the town unburdened by bodyguards. In reality the president only unscrewed the vent as a decoy and or prank then used an unlocked window to "escape".
  • Inverted — if only just — in real life basements containing an "egress window". This is intended to assist folks in their escape in the event of a house fire or emergency, but many folks often leave it open to get some air circulation going. Furthermore, many people are too large to make proper use of them.
  • Freddy Swanson, an inmate in Monterey County, California, successfully pulled off this trope in December of 2014.
  • In 1992, convicted murderer Richard Lee McNair and two other inmates escaped from North Dakota State Penitentiary by crawling through an air vent in an education room and making their way to the roof of the building. After crossing several more rooftops, they dropped 15 feet to the ground outside the main wall and escaped. The other two inmates were apprehended within hours, but McNair remained free for 10 months before being re-arrested.
  • Attempted by a pair of students in the US to steal an exam paper in the middle of the night. The air duct bit worked, but the tutor was working late.
  • A number of people have discovered to their dismay that air ducts and suspended ceiling grids are intended to support air and suspended ceiling tiles respectively, both of which are much lighter than human beings. Whether this discovery led to injury/death, imprisonment, or just embarrassment depends on where they fell through at.
  • Theatres not infrequently have "hidden passages" installed over the "house" (audience seating area) for maintenance and adjustment of lighting or sound equipment that would be difficult or awkward to reach in any other way. However, these generally don't "go" anywhere and you usually have to exit back out the same way you came in (A really enterprising person might rappel down from a catwalk, but anyone doing so would almost certainly be in full view of the audience and draw more attention than they would have had they just walked in the main door quietly.)

Alternative Title(s): Air Vent Infiltration, Air Vent Escape, Sneaking Through Air Vents