Our hero has found the Serial Killer's lair, complete with messages in blood and newspaper clippings of the murders. He needs backup, so he leaves the scene and informs the proper authorities. But when they get there, the room is bare, with no evidence that anyone was here. All the hero can say is, "It was here, I swear." Sometimes the killer has left some item to taunt him with, or a clue to the next killing.
The hero may not be tracking a serial killer, but could have uncovered evidence of a Government Conspiracy or the plan of some Diabolical Mastermind. It may even be evidence of some form of The Masquerade, an oddly-elusive Monster of the Week, or a Not-So-Imaginary Friend. The key thing is, the evidence won't be there when he returns. The fact that the witness loses all ability to communicate rationally doesn't help.
If the witness hadn't told the other person anything except "You've got to see this", then — after some moments of wide-eyed bewilderment — he may be reluctant to inform them of what he had really seen, for fear of appearing crazy or dishonest; he'll just say "trick of the light, I guess; sorry". The cleaned-up room may contain some mildly interesting thing that wasn't there before, leading the authority character to say "You rushed me here to see a butterfly?", or "Um, that's not a vampire, it's a picture of one."
Some The Men in Black shows have actual divisions called "Cleaners" or "Sweepers" for whom this is their entire job. To show up (in black vans, always) at a location filled with alien gore and debris and completely clean it up and remove all forensic evidence in 15 minutes or less. Maidservice on Steroids. Also, witnesses get Laser-Guided Amnesia or disappear. Sometimes The Men in Black will ensure the incident will be Mistaken for an Imposter.
Of course, the heroes will never actually walk in on the sinister government mooks or the brilliant serial killer in the process of cleaning everything away and thus catch them even more red-handed because there are No Delays for the Wicked.
Technological advances may eventually make this trope obsolete; after all, who today (in the First World, at least) doesn't have a cell-phone with a digital camera feature? Of course, writers already hate cell phones. In the rare case this is used, expect there to be a problem with the photograph--or the phone--that makes it useless. (If the photograph doesn't show the unusual thing at all, but is otherwise okay, either the phenomenon is immune to photography, or another trope is in play.)
- Big Store: Special case of this trope; a facade of a business set up specifically to trick someone.
- Cassandra Truth
- Devil in Plain Sight
- The Little Shop That Wasn't There Yesterday
- Nothing Is Scarier
- Not-So-Imaginary Friend
- You Have to Believe Me!
- Crying Wolf: Someone who says "It Was Here, I Swear" may be accused of Crying Wolf, but the audience knows that they're telling the truth.
- In the backstory of One Piece, probably the grandest and most tragic example of them all happened to the explorer Montblanc Norland, where he finds a legendary gold city on the island of Jaya, but when he goes back with the king of his homeland in tow, the island is gone (most of it, at least), having been knocked into the cloud kingdom of Skypeia by the Knock-Up Stream some time ago. Which, along with most of the crew dying from their own inexperience because they were the king's bodyguards rather than actual sailors, leads to Norland being executed, and him and his descendants becoming the subject of ridicule for centuries.
- Kanoko's corpse in episode 4 of Ookami Kakushi. Unusually, the person Hiroshi tells about it believes him anyway.
- A Misaka clone's corpse in episode 11 of A Certain Magical Index disappears by the time the police arrive. The police then berate Touma for "prank calling" them. Touma later finds that the other Misaka clones cleaned up the crime scene while he was busy calling the police.
- In Yu-Gi-Oh! 5D's, Jack Atlas gets held prisoner in a cave while an imposter commits crimes in his name. Jack eventually manages to escape and defeat the imposter. The next morning, Jack leads his friends to the cave, but is shocked to find the entrance has been replaced by a solid rock wall, and even the tire tracks from his Duel Runner are gone.
- Discussed in DuckTales the Movie: Treasure of the Lost Lamp. Webby's first wish on the genie's lamp is for a baby elephant. However, Reality Ensues when the elephant makes a gigantic mess after Webby can't control it, scaring Mrs. Beakley in the process. She goes to get Scrooge McDuck to show him, but by that time, Louie uses up one of his wishes to undo Webby's, making the elephant vanish and cleaning up the mess. Beakley even lampshades how crazy she must look after Scrooge finds nothing, saying "you think I'm crazy, don't you?" However, Scrooge sees his nephews sneaking out, replying "maybe not."
- In The Road to El Dorado, exiled ex-High Priest Tzekel-Kan is planning on revealing his city of gold to appease the recently arrived gang led by Cortez. Upon learning of this, Tulio and Miguel devise a plan that would bury the entrace to the city behind rubble, which would have the drawback of preventing them from ever returning as well. Their plan succeeds, and Tzekel-Kan is taken for being a "lying heathen", with nothing to show for his claims.
- Inverted in a cartoon where a woman is having a really bad day, and has to drive to the bank to get money (this was back before Automatic Teller Machines). She parks on the street out front, goes in and is standing in line, when the customer in front of her says, "I'd like to deposit $200 in pennies. One, Two..." as the line next to her moves forward. So she switches to that line when the person in front of her wants to deposit $300 in pennies, one at a time. Meanwhile, outside, the Department of Public Works decides to install a fire hydrant at the space right in front of her car. So she comes out to find a police officer writing her a ticket for parking in front of a fire hydrant. She pleads with the officer, by saying, "But officer, it wasn't here when I parked!"
- Zootopia: Happens when Judy tries to bring the police to the feral Manchas after she'd cuffed him to a post.
- Toy Story 2: Woody's friends arrive to rescue him after Al has packed up all the Woody's Roundup memorabilia. Woody tries frantically to make his friends understand just how popular the Woody toys had been.
Woody: There was a record player, and a yo-yo. Buzz, I was a yo-yo!
Mr. Potato Head: Was?
Buzz: Woody, stop this nonsense and let's go.
- In the film In the Line of Fire, Clint Eastwood's character is a Secret Service Agent, on the trail of someone determined to assassinate the American President. His first encounter with him is when a landlord notices her tenant has a "shrine" of sorts to other assassins. He visits the room, but when he comes back with a search warrant, the pictures have been replaced by a single one of him standing behind JFK, a president he failed to protect, a sign that It's Personal.
- Used repeatedly — and relentlessly — in the I Know What You Did Last Summer franchise. The scene where the murderer cleans a dead body and a hundred living crabs from a car's trunk in five minutes without leaving a trace of anything being there has prompted a joke that he could have started a very successful cleaning company if he hadn't gone Ax-Crazy.
- Scary Movie mocked the ability of the killer to get away with this so readily. Finding no blood or body at a murder scene, the protagonists argue over whether it really happened. Meanwhile, ten feet away, the killer — still in costume — is mopping up a trail of blood before dragging out a trash bag with a leg sticking out of it.
- Inverted in Gone in 60 Seconds (1974), where the protagonist is the leader of a group that steals cars, and in the process of stealing a car out of a man's garage, he spots them, but they take off. He gives chase at high speed, and is seen by the police. When he is pulled over, he tells the police the truth, that he was chasing a car thief. The police escort him back to his house, where his car is where it is supposed to be. So in this case he's trying to swear that it wasn't there. It seems that the guy they stole it from was the president of a crooked insurance company known for cheating people on claims, so he "temporarily borrowed" it in order to do some payback on the guy.
- In the film The Spanish Prisoner, Joe attempts to prove that Jimmy Dell actually existed by leading the authorities to Dell's suite of offices, only to find them abandoned. A bit harder to explain is the exclusive club Jimmy took him to which turns out to actually be a public restaurant.
- In the movie The Game, Nicholas Van Orton is sick of being toyed with by CRS. He calls the cops into their offices, but there's nothing there. CRS own the whole building and move their offices about for exactly this reason.
- In the James Bond film Moonraker, Bond discovers a lab where they are constructing satellites with deadly chemical agents. When he brings "M" and the police back there, everything is gone. The lab is replaced with a huge, opulent office. No explanation is ever given for how this happened. The lab was smaller than the office, so presumably one had been kit-assembled inside the other. Luckily Bond did have a vial of the nerve gas that the lab was working with.
- Subverted in the Get Smart movie: Smart discovers a secret uranium production facility in a bakery. 23 tells him that all that's actually found is a simple (though remarkably exaggerated) bakery scene — despite the fact that Smart, despite his failings, is an agent who pays attention to detail. This is used to imply that Smart is a double-agent. 23 in fact turns out to be a mole, who lied to both the Chief and 99 to discredit CONTROL. And even though the evidence is easily disposed off, he can't get rid of the tell-tale background radiation he's covered with so easily....
- North by Northwest provides a slightly more low-key example in which Cary Grant's character is mistaken for a government agent and interrogated with the aid of lots of carelessly poured bourbon; when he alerts the police and tries to convince them of his story, they return to a room devoid of any evidence of alcohol — or anything confirming what happened.
- The conspirators in Day Of Wrath have the hero doubting his sanity by committing grisly murders, allowing him to come across the scene of the crime, and then cleaning it all up before he can show anybody.
- In the movie The Manhattan Project, when Paul and his girlfriend try to enter his homemade nuclear bomb in a New York state science fair, federal agents capture and detain them there. Paul eventually confesses that the bomb is in his girlfriend's car, but it's gone when they all go down to the hotel's parking garage to get it. The bomb was stolen by a trio of other science-fair contestants who were eavesdropping on the initial interrogation, with the intent of keeping it out of the government's hands. They give it back to Paul later on when they rescue him from further interrogation and help him and his girlfriend get back to his hometown.
- Used to comedic effect many times in various Abbott and Costello movies. The film with the most abundance of it is Abbott and Costello Meet Frankenstein, in which slightly-eccentric Costello is constantly trying to inform straight-man Abbott about the existence/location of Frankenstein's Monster/Dracula/a secret room/Dracula's coffin, only to have it moved before he gets there (often within mere seconds).
- In the original Ghostbusters, Dana sees a temple and terror dogs in her fridge. When she brings Peter to investigate, he opens the fridge to find... junk food. In this particular case the explanation is supernatural, since it turns out that Dana lives "in the corner penthouse of Spook Central".
- In the Dragnet movie, Joe Friday and Pep Streebeck infiltrate a P.A.G.A.N ritual with thousands of attendees, a fleet of stolen public vehicles, a giant television screen, and a huge pit with a giant snake inside of it. After they escape by the skin of their teeth, they go back there with their boss... and there's absolutely no trace of anything there.
- In All Through the Night, Humphrey Bogart's character escapes from the headquarters of a gang of Nazi saboteurs during WW2. When he attempts to lead the police (who are skeptical of his story, as he's a mobster himself) back to the lair, it's been tidied up and all the swastikas, Hilter portraits, etc., have been removed.
- In Return of Count Yorga, Yorga sends his vampire brides to kill a family of his main target and then kidnap her. They do the deed and leave a murder scene behind which their maid, who happens to be mute, stumbles upon the next morning as well as the living survivor, the family's youngest son. She calls the police, but before they get there. Yorga's servant, Burda, drops by unnoticed and clears the scene so by the time the police get to arrive there's nothing left. She tries to get the boy to tell them but he, unfortunately under Yorga's control, denies her claims.
- Happens a couple of times to Goldie Hawn's character in Foul Play.
- Happens a lot in the French Fantômas films with Louis de Funès. The eponymous criminal mastermind loves to do this to the inspector chasing him. In Fantômas Against Scotland Yard, the inspector is staying at a Scottish castle. He wakes up in the middle of the night and sees a body hanging in his room. He runs out screaming. By the time he comes back with a crowd, the body is gone, prompting this trope. He next night, he prepares a camera on the nightstand. Once again, he wakes up to find a hanging body. Being smart, he snaps a picture and then runs out screaming. He does, however, make the stupid mistake of leaving the camera, allowing Fantômas to substitute it for an identical one with a picture of the room with no body.
- Inverted in Sky Captain and the World of Tomorrow.
Joe: It's a dead end.
Polly: That wasn't supposed to be there!
Joe: IT'S A DEAD END!!!
- In Beverly Hills Cop III, Axel Foley discovers a counterfeiting ring being run in an amusement park. When the authorities come to investigate, all they see being printed is novelty money for use within the park. There's also a subversion in which a seized van turns out to be empty, except for, as it later turns out, a crucial piece of evidence.
- In the film The Sentinel, the fugitive secret service agent has tracked down the headquarters of the real bad guys and killed several of them. He flees the scene, not wanting to get caught, but not before tipping off several colleagues in the hopes that the evidence they find in the apartment will clear him. Unfortunately, by the time the other agents get there, the other bad guys have managed to remove the bodies and the other incriminating evidence. To their credit, the other agents don't dismiss his story and are now less certain of his guilt.
- The Thing (2011). The female protagonist realizes that the alien shapeshifter can assimilate human beings when she finds blood and metal tooth fillings in the shower. She runs to warn the crew of a helicopter that's returning to civilization. The alien is forced to quickly assimilate them, causing the helicopter to crash. When she returns to the shower stall however, it's been cleaned up. While this removes the evidence, it also tells her that the Thing is still among them, and wasn't just on the helicopter.
- In The Number 23, the hero digs up a skull and leaves to get Police support. When they return the skull is gone and this trope comes in.
- Happens to Davey Osborne when the body of the government agent disappears in Cloak & Dagger.
- Our Man Flint. A taxi driver takes Flint to the offices of Exotica. After Flint is captured later, Galaxy operatives cause the building to sink into the ground and set up a cafe in its place. When the taxi driver brings the authorities to look for Flint, he appears to have gone crazy when he claims there was a building there.
- In the original Invasion of the Body Snatchers (1956), Miles breaks into Becky's home and finds a nearly complete pod duplicate. He gets her out, but when he returns with the police, the pod is gone.
- The remake Invasion of the Body Snatchers (1978) has a clever twist on this. When Matthew returns with the police, he points them to a window garden where the duplicate was. In it are several flower pots forming a vaguely human shape.
- Society: One of Bill's classmates tries to warn him about the suspicious stuff going on behind closed doors, and arranges to meet him at a location late at night. Bill finds the guy's murdered body in the trunk of an abandoned car, but when he returns with the police the evidence has already been removed. Said classmate set it up himself, and he shows up unharmed the next day to fuck with Billy's mind even further.
- In Vabank, it (a classy lady's apartament) was there in the evening, only to be replaced the next day by the workshop of an irritable tailor. Somehow Kramer's The Alibi suddenly stops holding water...
- In The Cobbler, after Max kills Ludlow, he turns himself in and returns to the crime scene with two detective. But now the body is gone and the blood-stained carpet looks clean. Max is flabbergasted and the detectives believe they have been taken for a ride by a lunatic. Little did they know, Max had a Mysterious Protector.
- Maurice in The Tall Blond Man with One Black Shoe finds the dead bodies of four agents in his flat and runs out. When he wants to show the evidence to François, all the bodies are gone.
- King of the Zombies: When Jeff first encounters zombies in the kitchen, he runs upstairs to tell Bill and Mac. When they come down with their host Dr. Sangre, they find a kitchen devoid of zombies, and the other servants swearing there never had been any. Bill and Mac dismiss Jeff as being concussed, or drunk.
- The House That Dripped Blood: In "Method for Murder", all of Charles' attempts to convince Alice that Dominick is real and in the house end with him showing her an apparently empty room and her thinking he is cracking up.
- In The Babadook, Amelia attempts to show the social workers the hole where the cockroaches were getting in, only to find a flat, undamaged section of wall. This makes her look even crazier.
- What a Carve Up!: When Ernie falls into the vaults and emerges from Uncle Gabriel's coffin, he goes racing back to the house to tell Syd and Guy that the coffin is empty. When the three of them return, Gabriel's body is back in place. Later, Syd takes Inspector Arkwright to the vault to show him Malcolm's body in Gabriel's coffin, only to find the entire coffin has vanished.
- Matt from The Power of Five becomes victim to this when he's living in the Town with a Dark Secret. Someone who believes Matt is brutally murdered, and Matt sees the room where it was done. He goes to get someone, and comes back less than ten minutes later. Everything is perfectly in order. Say what you want about the formula of Anthony Horowitz's writing, that was a freakin' creepy scene.
- In Lud-in-the-Mist by Hope Mirrlees, the protagonist and his friend discover a secret room in a public building lined with mysterious tapestries and filled with (illegally smuggled) fairy fruit. By the time they return with the authorities, the room is completely empty, much to their frustration. It is implied that this is because the first time they entered the room they accidentally gave the correct password while cursing at the locked door, while the second time they didn't remember what they had said and just broke down the door instead.
- Used in Killer when the girls tell the police about Ian's death, and his body is gone from the forest when they return.
- A few times in Galaxy of Fear. In the first book, people keep disappearing, even their footprints. This happens to some thugs chasing Tash, and her uncle tells her she just dreamed there were thugs and ran out of the house. During the second, whenever Zak tries to tell people about the zombies there's no longer any evidence. In the fourth book Zak comes across the Big Bad experimenting on people, and he's taken back to the place and told that it's an I Know What You Fear hologram machine. Later books have Zak, Tash, and their uncle all trusting each other enough, and made smart enough, to take these claims seriously, and this element phases out.
- In Murderess, Bridget tries to tell on Lu to the headteacher after the Snowball Fight; when the teacher arrives, Lu is inexplicably dry and even hot, and her clothes are all dry.
- The Lynburn Legacy: Intrepid Reporter Kami defies this trope because when she finds the aftermath of an animal sacrifice. Despite being freaked out, she makes sure to get a picture of it, then runs and calls the police, then publishes the picture in her paper.
- In Isaac Asimov's mystery novel Murder at the ABA, the protagonist discovers a small pile of heroin in the victim's hotel room. When he tries to point it out to the police investigator, it's gone.
- The Andy Griffith Show: "Mr. McBeevee," where Opie is initially unable to prove to his Pa that his new friend, a telephone lineman, is real. This happens in a scene where Andy suspects that Opie (who had described McBeevee in a typically enthusiastic childhood manner) had stolen a quarter that McBeevee had given him. Andy decides to take Opie to a work site where McBeevee had been working to back up his story ... but shortly before their arrival, McBeevee had been called away to assist on another project. Even in the face of certain punishment, Opie maintains his story.note
- Game of Thrones: In the prologue of Season 1, Will leads his fellow rangers to a circular array of wildling corpses, only to find they've all disappeared. We soon find out they got up and walked away.
- Happens a few times on Remington Steele by either Steele and Laura, or thier clients.
- One episode has Steele kidnapped at a mansion and nearly killed. When he returns with Laurel, Steele, a classic old movie buff, openly lampshades how he fully expects to find absolutely no evidence of what had happened. He's right.
- In the episode "One Giant Leap", Eden and Mohinder find Sylar's apartment, which has the message, "Forgive me. I have sinned" written in blood. When they return with the police, everything in the room has gone.
- Also, in "Ink," Matt who has Sylar's consciousness in his head so only he can see him ends up finding a stuffed animal, a ransom note from a hostage, a mind-read location of the victim and then the body of the victim found under the stairs. When his partner returns to find Matt beating the hell out of the hostage, Matt tells him to look under stairs and the body is gone. The ransom note and toy are gone too. Turns out Mental!Sylar used Matt's powers against him to make him see all that and thus have to use his powers to erase his partner's memory of the lack of evidence.
- I Dream of Jeannie had it as a Running Gag. Dr. Bellows knew something was up, but Jeannie always managed to pop things back to normal before anybody could corroborate his story. He was left looking like a raving lunatic.
- CSI episode "Anonymous" focuses on the hunt for a serial killer. Grissom concludes that the killer is Paul Millander, who owns a Halloween supplies company. When Grissom leads a raid on Millander's warehouse, it is bare apart from a stool with an envelope addressed to him. It has a blank piece of paper inside, a sign that Grissom interprets as meaning, "We have nothing."
- In "Mr. Monk Is Up All Night," Monk is walking in the middle of the night, and hears an argument behind a diner window. He peers into the kitchen and sees an apparent drug deal that's turning sour as two of the men are arguing about whether the third guy, an Asian is a cop. When the Asian suddenly flashes a badge and pulls a gun to arrest the others, a fight breaks out, and the Asian is shot dead by the drug dealer, who hustles a bald man to a car outside and drives away. Monk runs to a payphone to call the police, but the scene is spotless. That's because what Monk saw was an elaborate con game — the bald man was being tricked into thinking he had seen a cop's murder, so that three con men could trick him into giving them some of his antique coins under the pretense that it was hush money.
- Also used once as a clue in "Mr. Monk Takes a Vacation". It was the maids who killed one of the other maids to cover up their committing insider trading by viewing the belongings of business men staying at the hotel. Monk figured it out because they were the only people who could clean up a room that fast.
- In "Mr. Monk Goes to a Rock Concert," when Monk, Natalie and Kendra Frank are searching Stork's trailer, Kris Kedder snatches an incriminating envelope while they are distracted by Natalie noticing a photo of a little girl. Monk notices the envelope's absence after Kedder leaves and asks Natalie and Kendra if they touched anything, but neither woman has. Once Natalie finds a registered mail receipt, and Monk deduces that Kedder did not write a song they heard him performing earlier, Kendra belatedly realizes that Kedder has stolen the envelope and they need to get it back.
- The Invaders. About Once per Episode, any evidence that David Vincent could have gathered on the Invaders disappears before he can show it someone else.
- The X-Files
- Every. Single. Myth Arc. Episode. Oh my God.
- Arguably, this could be Mulder's catchphrase.
- Notably in "Je Souhaite", when Scully finally has solid proof of the supernatural in the form of the corpse of an invisible man. Of course, when she brings in the experts to look at it, it's completely gone. Just a few hours later, Scully herself starts to wonder if it was real, much to Mulder's annoyance.
- In the Babylon 5 episode "Passing Through Gethsemane", Brother Edward encounters the message "DEATH WALKS AMONG YOU" scrawled in blood on a bulkhead; it's gone when he tries to show it to Garibaldi. In fact, the message was a chemical that sprayed on the walls that looked like blood, then reacted with air and disappeared. Traces of it were found later in the episode.
- In Seinfeld, George Costanza gets himself invited to a night club populated almost entirely by beautiful model-types by... well, It's a Long Story. Once he shows up after losing his "credentials", the next day the same building is devoid of anything but a meat-packing plant.
- Defied when Shawn refuses to leave a corpse at its dump site because it'll be gone when they get back. They take the corpse with them instead, hiding it inside a school mascot uniform.
- Inverted in the episode "Extradition II: The Actual Extradition Part". Despereaux breaks out of prison to commit a crime, but by the time Shawn manages to report him to the authorities he's slipped back into his cell. The entire escape apparently went unnoticed.
- A variant appeared in Pushing Daisies where the body of Dwight Dixon undergoes a mysterious vanishing act from its grave, along with accompanying evidence that would have linked Emerson and Ned with his death. The body is later found in other (false) circumstances, planted by Ned's father to throw suspicion off Ned and his friends.
- Inverted in Season 1 of Life: the hero, Det. Charlie Crews has a locked closet in his home where he assembles evidence against the conspiracy that framed him. The DA's office obtains a search warrant for a related murder, and Charlie gets home too late to stop the search, but when the cops break into the closet, all the evidence is gone, having been removed by Charlie's roommate, Ted.
- There's an earlier episode in Smallville where Lana is chased by the "ghost" of a childhood friend. Said ghost turns out to be a clone, and they find a room filled with lots of clones of the same girl. But when the police gets there, guess it, it's goooone. The sheriff even tells Clark that "David Copperfield must have gotten there first".
- In one episode of Life On Mars, Tyler tries to prove he's not crazy by showing off many parts of his life that suddenly disappear, including Windy's apartment, where he informs her he wants her to talk with the people, and then when he brings them by to do so, the entire apartment is empty and Windy is nowhere to be found, nowhere near enough time passing by and making Tyler further doubt his sanity.
- The pilot episode of Stargate Atlantis, Sheppard and Rodney find the shuttlepod bay (eventually named "Jumpers"). Upon finding that Sheppard can pilot them, Rodney runs off to find Weir to inform her of the revelation. When they return, the Jumper is missing. After Rodney gives this trope's name, John uncloaks to impress Weir.
- Invoked in an episode of Leverage, "Three Days of the Hunter Job". Nate and the episode's bad guy walk into what she thinks is the apartment belonging to someone who is unraveling a government conspiracy, to find the material gone and Eliot coming out, cleaning up.
- Doctor Who
- Used in its standard version in "Black Orchid" with the Doctor finding a body and trying to tell someone about it. The first time he tries to tell someone it is indeed there, but the second time it's not. True to the trope, it's been replaced with a mildly interesting thing (a doll). Later he tries to tell the police about his TARDIS, and leads them to it. Of course it's not there either.
- Inverted in "Shada" where a man tells a police officer that a room has been stolen and so isn't there and of course when the policeman looks, it is.
- Also used in "The Keeper of Traken" when the Doctor explains that he arrived in the TARDIS. The Trakenites go to verify the existence of the TARDIS, but by then it's nowhere to be seen.
- Happens to Sarah Jane Smith in "Terror of the Zygons".
- In the second episode of Sherlock, John discovers a wall painted with graffiti that is vitally important evidence. By the time he finds Sherlock and brings him back, however, the evidence has been wiped clean. It's subverted, since that trick is a lot more difficult to completely pull off when people have camera phones that allow them to take instant photos of such things...
- Sherlock also believed John instantly, and was only concerned about how much of the graffiti John would be able to remember, since the human mind is on average only capable of remembering "62%" of what's it's seen. But the above spoiler solved that problem, too.
- One episode of The Rockford Files features a Stalker Shrine for Beth Davenport mysteriously vanishing before the police can see it.
- Immediately subverted: she says "I saw them," Lt. Becker says "I'm sure you did," usually a lead-in to a patronizing "you're just stressed" until he points to tiny holes in the walls, saying "They were put up with pins."
- Merlin regularly stumbles upon a Cassandra Truth. He either has no evidence or the evidence disappears.
- Inverted in "The Hunter's Heart" when he tries to prove Agravaine is a traitor by saying he stole the plans to the siege tunnels. When Arthur checks, Agravaine has already duplicated them and put the original back.
- A M*A*S*H episode has a variant of this. Klinger goes to a traveling black-market bazaar called "Little Chicago" to buy back a camera that was stolen from BJ and Hawkeye. On the way back he's nabbed by MPs for having stolen merchandise, and when he tries to take them back to "Little Chicago" to clear things up, the place has already moved on without a trace.
- On Bitten Philip meets with an amateur film maker who made a video of two wolves (actually Elena and another werewolf) killing a coyote in a park in Toronto. The film maker gives off a weird vibe but Philip just wants the video for use in a commercial so he does not inquire further. Some time later Philip wants to get more information about the video and goes to see the film maker. However, when he goes to the apartment where they previously met, it is completely empty. When he asks the landlord about the previous occupant, the landlord insists that the last tenant was an old lady who died months ago and the apartment has been completely empty ever since. The landlord further insists that no one could have been squatting in the apartment since the landlord was trying to renovate the apartment for new tenants and would have seen anyone living in it. This establishes that the conspiracy against the werewolf Pack is much more sophisticated and organized than just a few mutts acting out.
- In the Buffy the Vampire Slayer episode "Something Blue", Buffy discovers Spike searching the lawns near the college, claiming this was where he escaped from the Initiative, but there's no sign of any exit. He starts tearing at the grass, shouting threats and demands to be put back the way he was. Buffy naturally assumes Spike is just stalling and hauls him away.
- Murdoch Mysteries: Murdoch and Crabtree essentially say this when they bring the others to the yard where the dirigible had been based in "The Angry Red Planet".
- In Twin Peaks, Donna takes over Laura's Meals on Wheels route in hopes of finding more information out about Laura's murder. Her first client is a bedridden old woman with a very strange grandson. When she later brings Agent Cooper to talk to the old woman, a completely different woman answers the door who has no memory of any grandson or anyone else living there.
- Happens in Day Break, when Hopper wants to show the police the dead body in the bath tub above his apartment. It's gone by the time they get there.
- Murder, She Wrote: In "Tinker, Tailor, Liar, Thief", Jessica finds a body in her hotel room. By the time the police arrive, the body has disappeared. She later finds the corpse in the service area of the hotel, only for it to disappear again before the police arrive.
- Diagnosis: Murder: In "Misdiagnosis Murder", Jesse sees a man die of a heart attack in the parking garage. When he returns with aid, the body is gone and another man is faking tachycardia. Jesse spends the rest of the episode trying to persuade people of what he saw.
- Cannon: This happens in "A Lonely Place to Die", when the town drunk tries to convince the sheriff that a triple-murder occurred at the abondoned beach house next to his home.
- The Equalizer. A client of McCall tries to convince her daughter that she's dating a criminal after discovering a gun in his apartment. When she goes to show her daughter the gun, it's been replaced by an innocuous flashlight.
- Hunter. Hunter goes home after his shift ends to find a very beautiful and very dead woman there. Thinking he's being framed for murder, he leaves and gets his partner Dee Dee to come home with him so he can 'discover' the body with a witness. Only the body has disappeared by the time they arrive.
- ER. Carter treats a doctor who runs an inner-city clinic, visiting him there to check up on him and give him his medication. When the man returns to the hospital a few weeks later, Carter gives him a generous donation, but is stunned to find the clinic completely deserted when he visits again. The cop with him informs him that contrary to what the man told him, the clinic had been there only a few weeks, not the twenty-something years the guy claimed.
- On Magnum, P.I. (2018), a missing cat brings Magnum and Higgins to a ransacked house with a dead body. They call in the cops only to find the place cleaned up and the body missing. The cop makes it clear he'd be doubtful if it was just Magnum telling the story but Higgins backing it up sways him. He dryly notes that if Magnum should find a dead body "take a photo of it first."
- Older Than Steam: An interesting variant occurs in William Shakespeare's Macbeth, when Banquo's ghost appears during Macbeth's big banquet. No one else can see it, of course, and then it disappears while Macbeth is frantically trying to convince his wife that it's there.
Macbeth: Behold! Look! Lo!... If I stand here, I saw him!
- In Arsenic and Old Lace, the hero Mortimer Brewster, visiting his kindly old aunts' house in Brooklyn, is shocked to discover a dead body in the window seat. He's even more shocked later to discover that it's missing (it was taken to the basement for burial). It turns into a Running Gag when a second, completely different body shows up in the window seat, this time brought by his Ax-Crazy brother Jonathan.
- Arcanum: Of Steamworks & Magick Obscura; The (in)famous X-Files quest ends this (as well as You Have to Believe Me!) way: when you try to expose the conspiracy, you realize your proof was just, let's say, stolen. For added trauma, when you return to the secret facility where you found it, there's nothing, not even a brick.
- In Nancy Drew "The Final Scene", Nancy's friend is kidnapped and she knows the friend is being kept hostage in the building she's staying in, but the police don't believe her. She sees her friend tied up in a hidden room through a peephole, but by the time she gets there her friend is gone. There are still pizza boxes and her friends' shoe in the room and so she calls the police. However, she is later told that the police didn't find any of the things she found.
- Max Payne comes across an operation in progress, eliminating members of a conspiracy and any evidence of their existence. The assassins are even called "cleaners".
- In Yandere Simulator, if a Teacher's Pet student witnesses the yandere Villain Protagonist commit murder or sees a corpse, they will run to a teacher and lead them to it. If Yandere-chan moves the body out of sight before the teacher arrives, she will scold the student for pulling a prank on her.
- In the first chapter of Higurashi: When They Cry, Keiichi stayed home from school because he was starting to get suspicious of some classmates. Two of the girls from his school showed up that night to bring him some food and tell him they hoped he was feeling better. While eating the food, he choked on a sewing needle baked into a pastry. After having a talk with the police, the half-eaten snack containing the needle was nowhere to be found. Its unexplained disappearance would be creepier if it weren't the sort of thing his parents could've reasonably thrown out with the garbage. The hypodermic syringe is another, slightly creepier case in this arc, although at that point, of course, no-one was left to actually claim it as evidence. Eventually, it turns out the sewing needle and hypodermic syringe actually were paranoid delusions.
- Policenauts: Johnathan and Ed discover absurdly condemning evidence of Tokugawa manufacturing and concealing drugs only for everything to be gone when the police come four hours later. For added humiliation, them even finding the evidence was a trap, and part of a plan to frame Johnathan for multiple murders that stretched back before the game began.
- Referenced by Ivan Bezdomny in The Wotch, when he finds a cult of militant feminists in a secret sub-basement of the school.
Ivan: Forget it; if I go back for my camera, this will all be gone when I get back.
- The Simpsons
- Parodied in an episode of "Grift of the Magi", where Homer displays an unusual level of trope awareness:
Homer: Uh, is this going to be like one of those horror movies where we open the door and everything's normal and we think you're crazy, but then there really is a killer robot and the next morning you find me impaled on the weather vane? Is that what this is, Lisa?
- Used in the episode "Hungry, Hungry Homer", where the Springfield Isotopes' owner removes the evidence from his office closet. Just a trombone player giving him an appropriate flat note.
- Subverted in another episode, along with The Little Shop That Wasn't There Yesterday. When the family asks Homer where he got a cursed monkey paw, he says "I got it from that stall that was right over... there..?", realizing he's pointing to a empty alleyway on the last syllable. Then, the camera pans, showing the stall, and Homer continues "Oh wait, there it is."
"You'll be sorry!"
- Parodied in an episode of "Grift of the Magi", where Homer displays an unusual level of trope awareness:
- Used in Avatar: The Last Airbender when attempting to locate the headquarters of the Dai Li. The Dai Li destroy the main tunnel to their base, an easy job seeing as they're all earthbenders. It appears they also flooded their whole base at some point, since in The Legend of Korra it's completely full of water.
- Phineas and Ferb:
- This problem, used as a comedic device, continually plagues Candace; whatever amazing and bizarre thing Phineas and Ferb are doing that time, there's no sign of it by the time Candace tries to show Mom. This happening Once per Episode is the premise of the whole show. Phineas and Ferb's creations must have Plot Armor in reverse or something. Candace and sometimes Phineas and Ferb tries extremely hard to show Mom what Phineas and Ferb did, but the creations are always completely destroyed. Candace even "discovered" a nonexistent sensor that was buried in the family driveway and triggered a creation's invisibility.
- Likewise, Doctor Doofenshmirtz's daughter, Vanessa, attempts to show her mom (and his Ex-Wife), that Doofenshmirtz is an evil genius, but the evidence disappears. Ironically enough, it's shown that Doofenshmirtz's scheme (usually the B-Plot) is often what does away with Phineas and Ferb's thing, and when his scheme is the A-Plot, Phineas and Ferb do away with it.
- In The Movie, Candace is shown to be believing in a mysterious force that protects the boys. When the city is being attacked by killer robots, she knows that trying to show it to her mom will ensure they all disappear. When she finally drags her mom to the now empty streets the mom just watches in confusion while Candace cheers about how she saved the world.
- Defied in Justice League Unlimited season two, where half the season is about combating and investigating Cadmus, the shadowy government organization whose mandate is to prepare to take down the Justice League in the event that they overstep their bounds. When The Question is kidnapped and tortured by Cadmus the Huntress, recently kicked out of the League, goes to Superman for help and becomes frantic out of the fear that they will never find their headquarters. Superman, however, is perfectly at ease because the League already knows where Cadmus is. They have held off on actually attacking the base because they have been quietly amassing evidence in preparation for going public about Cadmus's true activities, and when the secret facility is moved after Superman and Huntress break in to rescue the Question the League know when and where they moved. Batman explains it pretty clearly when he points out that they have been monitoring Cadmus for months, so of course they have kept track of its whereabouts. Ironically, it is only Lex Luthor who is kept out of the loop, and when he betrays Waller and attacks the now-abandoned headquarters Batman uses that as evidence that it was not the League, since they would not have attacked an abandoned warehouse.
- Doom Kitty is prone to falling into this scenario in Ruby Gloom, where she is especially handicapped by only being able to communicate through (sometimes frantic) pantomime. Played with in "Doom With a View", when she tries to communicate to Ruby and her friends that a pair of ghosts are still in the closet in question, but unfortunately, only she can see them.
- Used and then avoided in the Kim Possible movie So The Drama: Ron is chased across town by a horde of tiny robots until he reaches the hall hosting the Junior Prom. When he opens the door, the robots hide. It looks like there's nothing there and Erik notes how ludicrous the claim is, but Kim chooses to believe Ron anyway.
- This is essentially Michigan J. Frog's entire schtick in Looney Tunes. This was the premise of both shorts Michigan J. Frog appeared in, One Froggy Evening and the sequel, Another Froggy Evening. He is, well, a frog that sings only for his owner, and the whole plot revolves around him being found, and performing so that only the person who found him ever sees it. Any time the man is actually about to get someone to witness it, he stops singing at just the right moment. Then the man is left to try and insist on his super special singing frog, only to be assumed a loon.
- This happened in the Adventures of the Gummi Bears episode "Toadie's Wild Ride". Tummi is the only Gummi in Gummi Glen to have seen Toadie enter the glen, but because he had been lying about who ate the cake that Grammi made earlier, the other Gummis initially don't believe him about there being an ogre in the glen. Subverted at the end when the rest of the Gummis finally see Toadie when he tries to make off with their supply of Gummiberry juice.
- Taz-Mania: Taz's attempts to convince Bushwacker Bob that someone is trying to murder them in "A Midsummer Night's Scream".
- Repeatedly subverted in Adventure Time episode "In Your Footsteps". Each time the bear does something strange, Finn acts like everyone else is missing critical evidence, only for it to turn out everyone already believes him.
- Used in the South Park episode "Obama Wins!" when Kyle leads the police to Cartman's bedroom only to find that the swing state election ballots that Cartman had stolen were gone. You Have to Believe Me! ensues.
- In the Scooby-Doo, Where Are You! debut episode "What a Night for a Knight", Shaggy and Scooby notice a missing spot on a museum wall. When they gather the others and bring them to the scene, the empty spot had been filled. "It was a minute ago," Shaggy pleads.
- In 2004, police on a training exercise in the tunnels underneath Paris found a fully operational movie theater/bar/restaurant, complete with professionally-installed electricity and sound. When they returned three days later, everything was gone, somehow snuck out through an opening the size of a drain.