A character swallows a key for safekeeping, whether to lock something or someone inside a device or room. Since you usually don't get something back once it's been swallowed, this typically serves as visual shorthand that the character in question has no intention of the lock it goes to being opened, ever. It also makes an effective way of enforcing that desire; whatever happens with that lock from this point onward, it's usually a safe bet that it won't involve that key being used to open it.
Subtrope of Eating Solves Everything. Sister-trope to Eat the Evidence. May be indicative of Crazy Consumption. See also Stomach of Holding, Extreme Omnivore. Compare Treasure Chest Cavity, Phlebotinum Muncher. Could be a rather unfortunate outcome of Pet Gets the Keys or Jail Bake.
- Played for Laughs in City Hunter. Kaori handcuffs herself with Ryo at one point to prevent him from getting frisky with their client. Unfortunately for them, the client's biggest dog sees Kaori twirling the key to the handcuffs and proceeds to swallow it, resulting in Ryo and Kaori being forced to stay close to each other, even when one of them must use the toilet, before they finally manage to procure the key again at the end of the arc.
- One of Jackal's men in Fist of the North Star does this in an attempt to keep Jackal from releasing the Devil's Rebirth from his cell. It doesn't work out that well though, as Jackal rips him open to get it back.
- A character in the manga does this as part of his hereditary Human Vault job; he can retrieve it easily if he has to. It's one of the many Nightmare Fuel moments if you think about how he'd have been prepared for the role.
- Mokuba does this as well, hence his Duelist Kingdom kidnapping in the manga. He claims the Big Five watched him every time he went to the bathroom, hoping it would pass. Eventually, they use an X-ray to scan his stomach and make a copy (why then never considered laxatives isn't clear) but when Yugi defeats Pegasus, this becomes redundant. (In the anime, he hides the key in his locket instead).
- Judge Dredd: Dredd does this in the story "Beat the Devil" in Judge Dredd Annual 1984 (and later reprinted multiple times) where he confronts the Devil and decides to arrest him. (The story is told in rhyme):
Narrator: Dredd said no more, but turned to the door,
Locked it and chewed up the key...
Dredd: Come easy or hard, the choice is your, pard—
But the only way out is through me.
- Y: The Last Man: Yorick does this trick as he is a trained escape artist, and he's taught it to his sister Hero, who uses a regurgitated key to escape prison. Played for laughs the first time Yorick tries it, as he vomits his lunch first.
- Done in the Coraline movie by the Other Mother.
- In Mickey and the Beanstalk segment of Fun and Fancy Free, the giant attempts to swallow the key when locking Goofy and Donald in a chest, but decides to put it in his pocket which Mickey soon retrieves.
- In Puss in Boots, Jack swallows the key that locks the box where the magic beans are kept.
- Bio-Dome had one of the Idiot Heroes swallow the key to the titular biodome to keep the project going.
- In Cube Zero, Dodd tears out a power coupling to prevent the villains from killing his colleague Wynn and swallows it when their leader Jax confronts him over this. Subverted, as Jax simply paralyzes Dodd and personally cuts it out of him.
- In Driving Lessons, Evie swallows the car key to stop the uptight Ben driving away. She does reassure him that it will be back in the morning, and she is as regular as clockwork.
Ben: Oh my God! You've swallowed the key.Evie: What a relief, he swears.Ben: You've swallowed the fucking key!Evie: Even better!
- Easy Street: When The Bully has the The Tramp trapped in his apartment, he locks the door and swallows the key so The Tramp can't escape.
- In the Mouth of Madness: Trent tries to leave town after the people turn into monsters and take Styles (who has been corrupted by Cane by then) with him, but she swallows his car keys. Trent punches her out and hotwires the car.
- In The Incredible Hulk (2008), when Bruce Banner is cornered by the Army at a university campus, he swallows a thumb drive containing vital data on his transformations so he won't risk losing it or letting it fall into the wrong hands. Amazingly, it still works after he... retrieves it.
- In Kiss Me Deadly, a woman with information the bad guys want is killed, but she leaves a hint with Mike Hammer that reveals she'd swallowed a key to finding the MacGuffin of the movie.
- Apparently forced on one of Jigsaw's captives in the original Saw, so that another prisoner could be required to cut it out of his body to stop her own rapidly-approaching demise. No, contrary to what she'd been told, the key-swallower was not dead when she started cutting.
- Done again in Saw 3D. The protagonist must free a woman from her trap, with the key in her stomach attached to fishing line coming out of her mouth, with fishhook included, so he had to be very careful when pulling it out or else the hook would tear her apart from the inside.
- In Superman III, Gus does this with the starter key to his machine after he realizes it's about to murder Superman. Unfortunately, the machine has a mind of its own and restarts itself.
- City of Thieves (1983): If you attempt to rob Ben Borriman the Silversmith, Ben will respond by swallowing the key to his cupboard where all his valuable silver is located before trying to fight you.
- In Joey Pigza Swallowed The Key, this is done by the titular character entirely by accident: he suffers from ADHD and develops a habit of putting the key in his mouth and then using the string attached to it to pull it back out just before he swallows it. When his exasperated teacher removes the key from its string to discourage this, he still unthinkingly puts the key in his mouth and since there's no string to retrieve it this time...
- In World War, due to the Lizards not understanding English expressions too well, they threaten to throw Rance into prison and "eat the key".
- In Yellow Blue Tibia the main MC swallows the key to his hospital room (many floors up) when an assassin tries to kill him. Then he takes a Geiger counter and points it at himself, activating it to demonstrate extremely high radiation levels coming from him. The assassin is trapped, and the very ill MC said it would be fun to do the chasing. He wasn't radioactive, just using the test button, but the freaked out assassin didn't know that!
- No Coins Please: Artie swallows the key to the briefcase containing his ill-gotten gains when he's about to be busted by FBI agents on his trail. Two x-rays later, the key is nowhere to be found... because he never swallowed it in the first place. He takes it out of his mouth when the agents point out that they're going to open the briefcase, with or without the key.
- Played with in an episode of 30 Rock, when Liz mimes locking her mouth and then swallowing the key. Jack then points out that that makes no sense.
- Angel: an ex-champion turned Death Seeker does this to ensure a demon will kill him to get it back; he's actually hidden it in a thermos of coffee, so the demon won't get what he wants.
- Arrested Development: GOB tries to do this in the episode "Key Decisions" to aid his escape from prison, but first has trouble swallowing the key and later is unable to pass it because of a Shy Bladder.
- In one episode of El Chapulín Colorado, evil pirate Alma Negra imprison part of his crew and and swallows the key so they can't escape. Parodied in that he even added some salt to the key before swallowing. Also a subversion since he actually needed to release them later on, and it wasn't until he swallowed the key that he noticed the flaw with his plan.
- Done accidentally in Coupling, when Jeff Murdock holds the key to his girlfriend's handcuffs in his mouth and then does his best Darth Vader impression. He spends the episode trying to find a way to get it out before she realizes what's gone wrong.
Jeff: (on laxatives) If I take all of them at once, do you think there's a danger of liftoff?
- In the CSI episode "Abra-Cadaver," the killer, a Stage Magician who was perfectly willing to kill his family members for the sake of illusions, does this at the end (although Grissom did think to check his mouth). Foreshadowed by a mention of the Harry Houdini example below.
- In one episode of Head of the Class, Dennis leads a protest in the cafeteria, handcuffs himself to a lunch tray rail at the serving line, and tells the teachers he swallowed the key. The janitor later has to cut the chain with a hacksaw to free him.
- In the pilot of The Invisible Man, villain Arnaud DeFöhn attempted to escape with the data on the I-Man project by swallowing a vital data drive when Darien confronted him. Unfortunately for Arnaud, by the time the drive had passed through his system his stomach acid had caused so much damage that the vital data was lost, preventing him from creating his own Invisible Man.
- In Jekyll, there's a scene where Claire swallows the key keeping Hyde locked up. (In this case, it turns out she didn't actually go through with the swallowing, and the key stayed hidden in her mouth.)
- Played with in The Mighty Boosh: in the episode "Jungle", Bob Fossil eats a key, slowly biting bits off it and chewing them.
- In one episode of Mystery Science Theater 3000, Pearl, Brain Guy, and Bobo are all trapped in a dungeon in ancient Rome. Bobo has the idea to regurgitate a key to undo their shackles, and Pearl compliments him for his ingenuity in lifting a key off a guard and swallowing it. Turns out Bobo didn't do that; he just thinks there's one in there because he swallows stuff all the time. It works, kind of — he found a hairpin after a while.
- In the NCIS episode "Dead Man Talking", a USB drive is found in the victim's (a fellow agent) stomach. The team realizes that the man knew he had only seconds to live and swallowed the disc so as to keep his killer from getting it, and knowing that the team would find it during the autopsy and use the evidence on it.
- Prison Break:
- In the first season finale, T-Bag handcuffs himself to Michael so that John Abruzzi and the other escapees can't get rid of him. He even swallows the key before it can be taken from him. In the end, Abruzzi frees Michael simply by cutting T-Bag's handcuffed hand off with an ax.
- In Rendezvous, when Bradley Bellick and Roy Geary are about to get the key to the locker where T-Bag has hidden Charles Westmoreland's five million dollars, he swallows the key. They end up getting the key anyway by tying up T-Bag on a toilet and feeding him laxatives.
- In Disney's Shake it Up episode "Show It Up", Flynn helps Deuce prepare for the talent show by suggesting he perform magic. During one trick, Deuce is chained to a chair and was supposed to have held the key in his mouth rather than swallow it.
- The Suite Life on Deck: In one episode Mr. Blanket, the school's insane Guidance Counselor, handcuffs Moseby and Zack together and swallows the key.
- Tales from the Crypt
- "Carrion Death" has a criminal and a cop that are handcuffed together. The cop is killed, but he manages to swallow the key before the criminal can get it, forcing the criminal to lug the dead cop along as he attempts to escape across the desert.
- Mr. Duvall of "Dead Wait" swallows a highly-valuable black pearl to keep Red from stealing it. Unfortunately, Red has a knife and no compunction about murder, so this backfires rather gruesomely.
- Not done intentionally, but El Blanco the Graboid ate a gangster in an early episode of Tremors: The Series, who happened to have the key to a mob safety-deposit box around his neck at the time. In a later episode, the gangster's surviving associate returns to try to kill El Blanco and retrieve the key, hoping to empty the deposit box of its millions.
- The televised Zorro with Duncan Regehr twisted this — at the end of one episode, he chained up the alcade in the town square and forced the alcade to swallow the key.
- King Smudge, from Fisher Price's Great Adventures Castle, does this in order to prevent anyone from freeing his brother, King McBeard.
- In Dragon Age: Origins, a man imprisoned on suspicion of desertion will offer you the key to a chest in exchange for food and water. When you ask why they didn't find it when he was arrested, he explains that he swallowed it, "but it's, uh...come back into my possession since then, so to speak."
- Final Fantasy XIV has the whale primal, Bismarck, eat floating islands to sustain its strength. One of the islands it swallowed happened to have a very important key to a floating city which both the protagonists and antagonists are hunting for. This creates a "damned if you do, damned if you don't" scenario; ignore the key while the primal continues to consume islands and eventually the planet's life force or kill the primal to get the key and risk the bad guys of coming in to steal it. The latter happens.
- Luigi's Mansion:
- In Luigi's Mansion: Dark Moon, Luigi has to deal with the playful yet mischievous Polterpup, who eats the items he needs to progress in three different levels. Each level ends with Luigi finally capturing Polterpup after traversing the entire area and chasing the dog throughout said area. The first two times, Polterpup manages to escape captivity, thus setting up his additional appearances, but after the third time, Luigi gets the dog sealed up for good.
- In Luigi's Mansion 3, Luigi is haunted twice over by Polterkitty, who pops out of the elevator control panel with the button he just tried to install, subsequently swallowing it whole and forcing him to chase after it. It gets away via detachable tails, but it only has so many of those. No need to ask why he doesn't try to use the elevator anyway; even if the hotel wasn't haunted, Luigi's a plumber, not an electrician.
- Early on in the game, one of the elevator buttons also repeatedly gets stolen and swallowed by some of the rats around the hotel, though they're considerably easier to deal with compared to Polterkitty.
- Mad Father: A good portion of the game is trying to evade danger, such as resurrected corpses and dolls, while trying to unlock the next area. At one point, underground, the player must find a key to progress past a door. The key is really easy to find. An undead dog then comes along and decides to swallow it. Then the player must go on a small quest to knock out the dog and cut open its stomach.
- Professor Layton vs. Ace Attorney: Dzibilchaltunchunchucmil does this in guarding the Bell Tower, which causes some problems in retrieving the key to unlock the door.
- One of Papa Morté's goons in Shadowman: 2econd Coming swallows the key to the Wild at Heart to keep Mike confined in the bar for what they hoped would be an easy hit job. Too bad for them, Mike quickly dispatches all the goons and simply retrieves the key from their splattered remains.
- In Shadows of the Servants, the doctor swallowed the key to a strongbox before she died. You can't open the box containing the ashes from her cremation, but can put it in the fireplace so everything except the key will be destroyed.
- Bob's Burgers: Subverted and lampshaded in the episode "The Wolf of Wharf Street", when Bob attempts to swallow the key after handcuffing Teddy to the table, because he's tripping on pain pills, and thinks Teddy's a werewolf.
- Dexter in Dexter's Laboratory does this in one episode when he discovered Dee Dee went through the secret bookcase entrance to prevent her from ever getting in again. Little does he know, however, he had also locked himself out of his own lab as well.
- In the Donald Duck cartoon "Trick or Treat", Don locks away all his Halloween candy in a closet and swallows the key. Witch Hazel then casts a spell on Donald's feet so that they kick out the key. (He then kicks the key under the door of the closet, annoying Hazel even more, who increases the spell's potency so his feet make him ram the door down.)
- Doug: In "Doug's Fan Club", Doug imagines locking up Todd and Wesley in a safe right before promptly swallowing the key.
- In an early episode of Ed, Edd n Eddy, Double D instructs Ed to hide the key. The guy slips the key between two slices of bread and eats it as a sandwich. Chewing and all.
- The Professor in Futurama did this with the spaceship keys to stop anyone from wasting fuel, only to "recover" them the next day.
- Hi Hi Puffy AmiYumi: In "Arbor Day", Ami chains herself, Yumi, and Kaz (the latter two were not as willing as she was) to a tree to prevent the bad guy from cutting it down. She then swallows the key to the padlock on the chain, and after the bad guy learns his Green Aesop, she expels it on command by hiccuping.
- Looney Tunes:
- In the short "Fin n' Catty", a cat corners a fish inside a shower, so he locks the door and swallows the key. Only then does the cat realize the shower stall is filled with water (which cats hate, as everyone knows) and he tries to punch the key out of his stomach.
- In the short "Hyde and Tweet", Sylvester did this after finally capturing Tweety. Only after Tweety's transformation does Sylvester realize that he's trapped.
- Robotboy: Gus did this twice, first to stop Kurt from using the bathroom so Tommy can torture him for Robotboy's whereabouts and second while Tommy burns the containment unit holding Robotboy imprisoned (Ironically, the second example ended the episode with Constantine and Dr. Kamikaze locked outside of their submarine lair).
- The Loud House: In the episode "Diamonds are for Never", Lola and Mr. Grouse are fighting over who gets to sell a diamond they found. At one point, Mr. Grouse locks it in a box and swallows the key, to Lola's shock. He tells her not to worry, he eats a lot of fiber, so it won't be inside him for very long, to which Lola reacts in disgust.
- In the Silly Symphonies short Three Little Wolves, the Big Bad Wolf, disguised as Little Bo Peep, traps Fifer and Fiddler Pig in his house, locks the door, and swallows the key. Both Fifer and Fiddler turn red, implying they think they're about to get lucky, but this is when the Wolf reveals himself.
- The Simpsons: In "On a Clear Day I Can't See My Sister", the manager of the Sprawl Mart locks his employees inside the store, and then taunts them by swallowing the bathroom key.
- Storm Hawks: Stork tries to keep the Raptors from getting their hands on a Graviton Crystal by swallowing it.
- Taz-Mania: Taz does this after he has cornered Francis X. Bushlad (who is Disguised in Drag as an attractive female Tasmanian devil) in "A Young Taz's Fancy".
- In one Tom and Jerry cartoon where they were doing their take on Robin Hood, Tom swallowed the key that went to Robin's cell.
- Harry Houdini was reputed to do this with a handcuff-key in preparation for his escape act, then regurgitate the key when needed.
- It should be noted that most keys are made from alloys containing a fair amount of lead and it's not the best idea swallow a key with a lead content.