Ten Little Murder Victims

"I know I'm human. And if you were all these Things, then you'd all just attack me now, so some of you are still human." —R.J. MacReady, The Thing

A group of people are invited to attend a get-together, usually held at an Old Dark House often in the middle of the lush country side or (more recently) on someone's Private Island, by a mysterious and/or eccentric host. Suddenly one of the guests (or even the host) is murdered and circumstances prevent the others from leaving, usually a heavy storm or a cut bridge, or even both.

Our heroes soon learn that one of their party is actually some manner of villain (typically The Mole, though a random escaped criminal is not unheard of), but, for various contrived reasons, that's all the information they're going to get. So it's up to them to work out which of their supposed colleagues is really The Mole before he can kill them all. And you can't trust anyone until you do. Luckily, however, there's (usually) only one mole involved.

Often results in everyone being Locked in a Room. This can be self-imposed, as our heroes can't chance The Mole reporting back to headquarters, but a Genre Savvy enough character may force this upon everybody, which will usually raise everybody's tension. Circumstances will always contrive to prevent our heroes from getting in touch with the outside world to find out who The Mole is, which may range from the aforementioned storm knocking out the telephone poles, to someone cutting the telephone lines, to outright smashing all the phones to pieces. Accusations are hurled, secrets are uncovered and more murders are committed as the Dwindling Party tries to determine who is the murderer in their midst.

In a well-done example, the audience will work out who The Mole is only seconds before the heroes do, though they'll typically be led to an incorrect guess from early on.

Non-recurring characters are subject to being killed off one-by-one by The Mole. Of course, strictly speaking, no one is above suspicion, even our heroes, and at least one member of the group will panic, accuse the heroes, and run off to a certain demise. The audience (usually) knows better.

Named after the 1939 Agatha Christie novel formerly titled Ten Little Indians.

Often the modus operandi in a Reunion Revenge. If the writers are really bloodthirsty, it only ends when they Kill'Em All (or, if you're at the beginning of the series, Everybody's Dead, Dave); if they're feeling devious, they may also throw in a few instances of Suspect Existence Failure. Don't be surprised if a Mexican Standoff or two pop up, especially for the finale.

Examples of Ten Little Murder Victims include:

General outcomes of this plot

• A: One person will seem to actively hinder the investigation. He'll drop the radio, breaking it just before a description of The Mole is broadcast. He'll have a panic attack at a critical moment endangering the group. He'll be suspiciously uninformed about whatever his job is supposed to be. This person is never The Mole. He's just an idiot. (See Hanlon's Razor.)
• B: One person knows his job well, but he's a little high-strung. He accuses a lot of people of being The Mole on shaky grounds. If it doesn't turn out that he's the Mole (which is a little too obvious, and therefore rare), odds are the real Mole's going to kill him.
• C: One person is very competent and helpful. He'll even have some extra skills that are handy for just the room in which they are locked. He might even find clues as to The Mole's identity. At some point, he'll save the hero's life. He's The Mole, and he's really very good at it.
• D: The idiotic Red Herring Mole turns out to be a spy for the good guys. He's been keeping it a secret since, like everyone else, he's not entirely sure that the mole isn't one of the heroes. His apparent incompetence is really Obfuscating Stupidity, and he's trying to goad the real Mole into tipping his hand.
• E: There's a second mole — perhaps even one that the first mole doesn't know about.
• F: None of them are The Mole: the initial message was a fabrication by the bad guys to make the heroes turn on each other.
• G: None of them are The Mole: the hero has been hypnotized to act as mole without even his own knowledge, or is simply an Unreliable Narrator.
• H: The Mole successfully frames someone else.
• I: No one is The Mole: for whatever reason, everyone's paranoia has spiraled completely out of control, causing them to attack each other on otherwise flimsy pretexts or misinterpreted accidents. Or the host, with the help of his staff and/or associates, faked it all to "entertain" his guest.

Anime and Manga

• In Episode 5 of Azumanga Daioh, Osaka imagines one of these happening at Chiyo's summer home:

Osaka: And then it turns out... I'm the killer! Yomi: Why do you get to be the killer?

• In the Lone Island Syndrome episodes of Suzumiya Haruhi the SOS Brigade goes on a club field trip to an island mansion specifically set up to this trope.
• The first Gall Force does this without the murders. Each cast member is offed by differing circumstances as they try to make their way to the planet Chaos. The mole was Catty, but she was only trying to arrange for one of the others to get a Face Full of Alien Wingwong in the name of galactic peace, and didn't actually try killing anyone. She sacrifices herself halfway through to let the other survivors get to an escape pod. A self-parody short of the entire series is even titled Ten Little Gall Force.
• In volume 30 of Case Closed, Captain Ersatzes of famous detectives were invited to an abandoned mansion and die off one by one. Only one of them actually died. The rest faked their deaths once they deduced who the real killer was in order to Pull the Thread on her.
• Moto Hagio's They Were Eleven has this happening during a survival test where ten students are stranded on a derelict spaceship...so why are there eleven of them? Everyone knows that one of them shouldn't be there as accidents keep happening, and the hero has the additional problem of fitting the "competent and helpful" rule of Mole detection above — as the other students begin to notice. Everybody Lives. The extra examinee was an instructor sent in as The Mole to cause trouble and force the group to quit the test, as a Secret Test of Character for all of them; things got out of his control. The hero's suspicious knowledge of the ship was because he was unknowingly a survivor of the disaster that originally destroyed it.
• Between Umineko no Naku Koro ni's Succession Crisis and a bizarre riddle counting off the visitors' horrific deaths in a witch resurrection ceremony, the characters can't figure out whether they're being bumped off by each other or demons from hell. And the author isn't helping, making this one a zig-zag.
• Only one murder so far - well, almost two - but the latest chapters of Black Butler are following this trope's description to the letter, complete with large, dark mansion, gathering of wealthy guests, and the raging storm that means no one gets to go home. (And this troper considers Ciel fitting enough for the role of 'mysterious host'.)
• Urusei Yatsura had an anime only episode where the group was killed off one by one till only Ataru was left In the end, it turned out the murders and complicated reveal of a killer with Ataru's face were a complicated plan by the perfectly unharmed victims to "Fix" Ataru's personality. The ending makes it pretty clear that Ataru saw through it at some point and proved to be a better actor than they had realized.
• In a chapter of Franken Fran, Fran is invited by former patients for a party in a remote location. Soon, they are attacked one by one - hopefully, Fran can save them. This being Franken Fran, the truth is far more disturbing than expected. Even Fran finds it disturbing.
  • The answer? The victims are doing it to themselves because they get off on Fran operating on them.
• One of the filler arcs from Bleach featured this. Ichigo's group of friends have to get through a series of games, one of which involves a member of their group being kidnapped and replaced by an shapeshifter. It turns out to be Chad.
• The manga Rabbit Doubt was a version of this, but with hypnosis magic. The real killer hypnotizes another and has her confess, then escapes.
  • The sequel/spinoff, Judge, does this as well.

Board Games

• The entire premise of the board game Clue, as well as The Movie based on it. The film involved a group of guests with questionable pasts being locked inside a mansion trying to figure out who killed Mr. Boddy. Every single one of them had a motive to kill him, and things aren't helped when the rest of the mansion's staff begins falling like flies...
• Parodied in the board game Kill Doctor Lucky, by Cheapass games, the objective of which is to be the first to bump off the good Doctor. The players all despise Doctor Lucky, and have been invited to his country mansion for the weekend. In the words of the game "There's a howling storm outside, it's midnight, and someone just shut off the lights..."

Comic Books

• Parodied / subverted in a Doctor Who Magazine comic strip, in which a group of minor villains that the Doctor has previously defeated gather together in a deserted space-station to plan a final attack that will finish him once and for all. One of them dies horribly, and as the others begin dying one by one afterward, it seems (to them, anyway) as if the Doctor has infiltrated their midst in disguise and is picking them off one by one. Finally, the last couple — paranoid that either one of them could be the Doctor in disguise — kill each other... and at that point, the Doctor arrives, not recognising any of them. Turns out the first death was just an accident with a faulty machine and the other deaths were just everyone picking each other off out of sheer paranoia.
  • Played straight in an earlier Eighth Doctor strip.
• Happens to the Club of Heroes in "The Black Glove" arc in Batman.

Fanfiction

• This trope is the most popular mystery outline for any fanfiction category (there are even fanfictions under the trope namer's category using original characters for the plot) thus making any possibility of listing all examples ludicrous.

Film

• Murder By Death is the Affectionate Parody of the genre; here, the guests are thinly-disguised versions of famous fictional detectives. The trope is averted when it turns out the villian isn't really interested in killing them off, but in embarrassing them instead.
• Alien 3, which has been described as "And Then There Were None in outer space" by Entertainment Weekly, had the entire population of Fiorina 'Fury' 161, save for one prisoner (Morse), killed off by the xenomorph that had infiltrated the prison. This includes Ellen Ripley herself, who died as a combined result of the chestbursting chewing its way out of her, and a suicide dive into the prison's metalworks.
• April Fools Day. There's even little dolls representing the guests, prompting one to say that it's "like something from Agatha Christie".
• By the end of The Lady Killers, the robbers have all killed one another except the Professor, who is struck on the head by a railway semaphore. Little Mrs Wilberforce is left with all the "lolly".
• The film adaptation of Clue was essentially a gigantic parody of this trope.
  • The last one of the three alternative endings subverted the trope by revealing that everyone except The Mole was a murderer.
• The Bollywood movie Gumnaam is an uncredited remake of And Then There Were None.
• The bank robbery in The Dark Knight might be considered a high-speed variant of this, as one robber after another kills an accomplice, then is killed in turn. Unique in that it takes place at the scene of another crime in progress, and the guy who figures out what's going on ("Let me guess: you're supposed to kill me?") is immediately killed.
  • But not by the guy who he thinks is supposed to kill him.

Joker: No. No, no, no, I kill the bus driver. Grumpy: Bus driver? What bus dri-? (bus drives through wall and hits Grumpy, killing him)

• The '80s version of The Thing, and the short story both versions were based on, Who Goes There both combined this trope with The Virus.
• Another alien-invasion movie example: The Faculty; the humans who have not (yet) been taken over by alien parasites regard each other with suspicion and must figure out who in their number has fallen under alien control... but more than that, they must determine which person has actually been an alien all along. Not really surprisingly, the one who is an alien rather than an alien-controlled human is the "new girl," who has been giving the other students a Backstory they've had to take on faith, rather than having a known history in their community.
• Identity is a variation of this. 10 strangers meet in a remote hotel, where they start getting killed one by one by a killer, who is presumably one of them. At first the trope seems to be played straight, as the helpful, authority figure cop is revealed to really be a criminal and a killer. However, at the end, it's revealed that the killer who was actually killing the guests was the little boy. This makes sense because the characters are all personalities inside the mind of a serial killer with multiple personality disorder; the little boy is the murderous personality, representing the abuse the killer experienced as a child.
• D-Tox was a film with this premise, starring Sylvester Stallone. Stallone was one of 9 cops being treated for psychological problems at a remote ranch in snowy Wyoming. However, one of the other patients was actually a serial killer who targets cops, having killed the real patient and assumed his identity. I forget the specific identity of the real killer, except that he turned out to be the character who was most apparently helpful and mature (as opposed to the cowardly guy or the violent alcoholic).
• Mind Hunters was another film with this premise, about several FBI students being trained as criminal profilers at a remote training facility. One of them is actually a serial killer killing the other characters off one by one. Of course, the killer turns out to be the heroic, helpful, supportive Alpha Male of the group.
• Reservoir Dogs, in which one of the robbers may (or may not) be setting the others up.
• Where Eagles Dare has not one, but three of these. Four if you count the Colonel.
• Fantastic Voyage establishes that at least one of the crew of the Proteus may be a Soviet agent sent to finish the assasination attempt on the scientist the mission is meant to cure. Violating the first rule of mole detection above, the character played by a sweaty, nervous Donald Pleasence who tries to open the hatch of a submerged submarine as soon as they're shrunk is the traitor (Or just a claustrophobic man in a cramped sub who went off the deep end trying to get out — the movie never says for sure.)
• Before the Liam Neeson flick of the same title, a film called Unknown combined this with Easy Amnesia and Paranoia Fuel. Several men, some of them kidnappers and others, their kidnappees, wake up with no memories and find themselves locked in a warehouse, having all been overcome by an accidentally-released toxic gas. A brief phone call from the kidnappers' accomplices reveals that more thugs will arrive soon, and presumably kill the ones who aren't on their side, but none of the trapped men know if they're the culprits or the victims...

Literature

• The Strugatsky Brothers' Hotel of the dead alpinist seems to start this way... and then things get weird.
• The novel The Man Who Tried To Get Away by Stephen Donaldson is one big heavily lampshaded exercise in the trope. Private eye Brew Axbrewder is running short on cash and needs to lie low after treading on the toes of a local crime boss, so he reluctantly agrees to be a consultant and participant for a murder mystery vacation in a lodge out in the woods. He (predictably) hates every minute of the contrived And Then There Were None event, right up until one of the participants gets killed for real. And someone has cut the phone lines. On a blizzard has blocked the only road back to town. Axbrewder and his partner assume that the crime boss has found out where he is and sent someone to take out Axbrewder and kill all the witnesses, but he's only half right. The crime boss does have a hitman at the event (the maintenance man, who gets sent out to try and walk back to town, turns out to be working for him), but neither our hero or the detective know that two of the guests are actually violent psychopaths who booked into this vacation for kicks, and it's they rather than the hitman who kill most of the other guests.
• Parodied in Anthony Horowitz's novella I Know What You Did Last Wednesday.
• Played with in the teen horror novel Class Trip by Bebe Faas Rice. The Ten Little Murder Victims plot is related in first person by one of the characters. Eventually there's just two of them left, and the police are on the way. The narrator then reveals that she was the killer all along. However, before she can kill the last remaining character, he reveals that he tape recorded her Engineered Public Confession even though he didn't intend to. She starts crying as the rescuers arrive as she realizes she is caught.
• The book and movie version of The Ruins has this trope as a central plot point. In the book, all of the characters are killed by a man eating, parastic vine.
• Several of Simon R. Green's Hawk And Fisher stories use this trope. His Secret Histories novel The Spy Who Haunted Me has a variant that plays out among spies held together in a group by the terms of their mission, rather than by geographic isolation.
• A variation happens in Murder on the Leviathan, which was intended as a tribute to Agatha Christie; what makes it unusual is that this situation came about when a detective looking for a murderer on a luxury liner had his chief suspects assigned rooms in the same salon. And then one of them was killed.
• Ten Little Wizards, a Lord Darcy novel, is an homage to Christie's version. A subversion, in that the killer's countdown doesn't make it to "none", and the apparent killing spree is an Evil Plan by Polish spies.
• Old Tin Sorrows
• Ripper is Michael Slade's take on this trope, with the added twist that the guests are all mystery writers and there are two killers working together, not just one.
  • Also, because The Mole kills with pre-rigged death traps, even figuring out who it is won't guarantee safety: the traps will still be lethal.
• Possibly the ultimate literary example: Agatha Christie's And Then There Were None, a.k.a. 10 Little Indians. The Mole is Justice Wargrave.
• In the Star Trek novel Kobiyashi Maru this was a training scenario for Starfleet cadets. Several dozen cadets were dropped on an abandoned moonbase, and told that one of them was The Mole. Their teachers then sat back and watched what the cadets did. Typical behavior was to band together into small groups, and end up fighting against other groups because one of them could be The Mole. Chekhov's solution was to simply kill EVERYONE (at the end of the training, all his victims assumed he was the Mole. He thought he was the winner. The teachers explained he was simply a very skilled assassin (and a bit of an idiot)). Turns out there was no Mole, the scenario was designed to emphasize the dangers of distrust and paranoia. He was then told that his hero, a young captain named Kirk, had come up with a working solution; he invited all groups to join his, but the condition for joining was that everyone would be disarmed. The exception were two guards selected by Kirk; if one of them happened to be The Mole, the other could just shoot the guy.
• In Maurice Leblanc's first published Arsène Lupin short story, L'arrestation d'Arsène Lupin, the passengers of a transatlantic liner learn by telegram that the famed Gentleman Thief is travelling in first class under an assumed name. All they know is he is blond and his fake name begins with R. The story deals with the idle young nobility on board trying to unmask him from those clues while various precious objects are stolen around them ; until the ship arrives and Lupin is revealed as the narrator, who was not blond and whose name did not begin with R, but who planted false clues to mislead the police.
• Used to some extent in Dune, with a letter throwing transparently false suspicion on Jessica. No one in House Atreides suspects Yueh of being The Mole at all, though he's already been identified as such in the narrative (it's presented as a mind-blowing revelation in-universe due to his loyalty conditioning).
• A major plot thread in the second Mistborn book-it appears for much of the book that one of the main characters has been replaced by a kandra, a creature that can consume a corpse then animate it and imitate the person in question almost perfectly. Despite assistance from her own kandra, it takes Vin most of the book to figure out who it was. As was stated on the main Mistborn page, The Reveal is quite brilliant.
• Subverted in The Dresden Files book Dead Beat, where Harry quickly and decisively identifies the current body of the Corpsetaker within seconds of his/her/its body-hopping.
• Something like this plays out in Kitty's House of Horrors. It's all a subversion. The panicky, incompetent, suspiciously underinformed person isn't the mole, but survives anyway. The competent but high-strung person who constantly accuses someone else of being the mole isn't the mole, and also survives. The helpful, amiable person with lots of useful abilities isn't the mole either. No one is. However, almost everyone besides those three and the narrator dies. Everyone in the house was an intended victim.
• Subverted in Jo Walton's Alternate History novel Farthing, which is set up as a classic country house murder mystery, then is revealed to actually be a political conspiracy.
• In L. Jagi Lamplighter's Prospero Regained, the Prosperos have been told they have an in-family traitor. One of the things they try to unearth while descending through Hell to rescue their father.

Live Action TV

• The Adventures of Brisco County Jr. ("Bounty Hunters Convention")
• The Facts of Life parodied the trope by having the victims killed in silly ways (Blair was killed by over-using hair spray, Natalie was strangled with a pair of fuzzy dice). In the end, it turned out to be All Just a Dream (a Dream Within a Dream, in fact).
• Get Smart ("Hoo Done It")
• Remington Steele had at least one of these, with Steele of course referencing And Then There Were None and its signature plot twist: the sixth person to 'die' faked his death and was actually the murderer.
• Funny Subversion: Homicide: Life On the Street once had a murder at an exclusive country club, that appeared to be one of these. After a Christiesque setup and a cutaway, the BPD detectives had the case closed by the commercial break.
• Harpers Island. With 29 deaths on screen and, out of the main cast, 4 survive. Two (Shea and Madison) are The Scrappy.
• Stargate SG-1 features such an episode, only instead of a building, they are all stuck on the Alpha Site planet and unable to leave until the murderer is found. Tensions mount between the three races present, with the leaders under a lot of pressure to keep it from turning into a shootout. Accusations are flung around and the humans are stuck in the middle. The murderer turns out to be an invisible Ashrak, but the relationship between Earth and its two allies never quite recovers.
  • The episode "Proving Ground" took the theme Up to Eleven. Given that the SGC's primary foes are Body Snatchers, they select new members through complex training exercises where Everyone Is a Suspect Mole. These exercises tend to be Total Party Kills. One particularly promising group that refuses to get their act together finds that their umpteenth test is Not a Game. It was a game with one of their own being a Reverse Mole whose job was to up the ante. When they knew it was all a game, they slacked off. When they thought it wasn't, they ended up distinguishing themselves under fire and becoming a quality team.
  • In another episode, they knew who The Mole was, but it had an annoying tendency to Body Surf. That meant no one could be trusted- just because you weren't The Mole two minutes ago doesn't mean you're not The Mole now- and required some extreme measures to resolve.
• The Wild Wild West episodes "The Night of the Tottering Tontine" and "The Night of the Bleak Island".
• The Avengers episode "The Superlative Seven".
• An episode of CSI has the forensic team trying to locate a gang of casino robbers. The CSIs find that each gang member was killed by one of his or her partners, and end up following a trail of dead bodies to the last surviving robber.
• Played with in an episode of Highlander the Series where Hugh Fitzcairn is killed and any one of his half a dozen or so houseguests could have done it. However, as he is immortal, he revives and spends the rest of the episode annoying MacLeod, who is trying to find the murderer without giving away the fact that he's still alive.
• Parodied in The Goodies episode "Daylight Robbery on the Orient Express".
• Mathnet (from Square One TV) did an episode like this that was both a parody (the villain turned out to be a court stenographer) and an homage.
• One Boy Meets World episode (Called "And Then There Were Shawn") features this plot, with the characters stuck in detention (caused by a quarrel between the main characters) and soon being killed by a mysterious murderer within the school, (including one by the name of Kenny. In the end, Shawn rips off the mask of the killer to reveal that it was him under the mask all along. Then it's revealed that it was all just a dream had by Shawn.
• Parodied in Frasier when the station is redoing an old radio drama. It was clearly supposed to be like this, but Niles (who was forced to take on multiple roles, including the murderer, at the last second) finally gets sick of Frasier's overdirecting and "kills" every other character in under a minute, before doing himself in cheerfully proclaiming that the secret of the mystery will die with him, leaving Frasier (as the detective) to desperately close the thing out.
• MacGyver: "The Invisible Killer". Just as Mac determines which of the Phoenix employees on his wilderness stress-relief retreat is an imposter, we find out that not one but two of them are really escaped convicts.
• The Twilight Zone: "The Monsters Are Due On Maple Street". A street in a small town loses all power and use of their cars. Spurred on by a young boy's claims that this is a common comic book plot, they quickly suspect each other of being aliens. As riots break out, the audience learns that, no, none of the folks on Maple Street are aliens. The whole thing was set up by alien puppetmasters outside of town to trigger the riot, who comment on how easy conquering Earth this way is. Replace "aliens" with "terrorists" and "alien puppetmasters" with "US Army researchers", and you get the version used in the 2002 remake.
• First Wave did this numerous times and in every variation. They added the further complication that the hero himself was usually also an impostor in the group, and had to spend much of the episode convincing the others to trust him.
• War of the Worlds also did a number of variations on this. The most straightforward instance was "The Last Supper", complete with the undercover spy who initially appears to be a shoo-in for The Mole.
• The Mole implemented this concept as a Reality-based Game Show. Thought the show the contestants are faced with several challenges which, if completed successfully, earn money that goes to a global pot. However, as the name indicates, one of the contestants is a Mole hired by the producers to make sure they win as little money as possible. Contestants are eliminated via a quiz at the end of each episode that asks several bits of biographical information about the Mole: the person who gets the least amount of questions right is eliminated.
• The second season of Who Wants to Be a Superhero included such a challenge. Given that there were two actors planted amidst the first season contestants (both The Mole and a scheduled Face Heel Turn), this was a believable threat for the heroes and the audience. But it turned out to be a false one; all the contestants were for real this time, and Stan just wanted to see if they'd go into witch-hunt mode.
• In the Star Trek: The Next Generation episode "Allegiance", Picard found himself in a similar situation to the Star Trek novel example, where he and three strangers are left in a cell with hints that one of them is working for their captors. In this case, not only was one of them the mole, but an impostor Picard was also placed on the Enterprise to run an experiment on the crew.
• Subverted in an episode of Monk. After breaking into a woman's home to find her being drowned by her identical twin, Lt. Randy Disher asks which one's the real one. Captain Stottlemeyer suggests arresting the one that wasn't drowning.
• In the season 6 opener of NCIS, we learn that Agent Lee is The Mole, but the team thinks it is Agent Langer, who Lee frames and then kills. Later, they figure it out and it ends in Redemption Equals Death.
• On WMAC Masters during a Dragon Star match between Hakim "The Machine" Alston and Ho Sung "Superstar" Pak someone wearing a ghost town ninja outfit eliminated both of them and the other masters figured out early on that one of them had to be the masked ninja. They suspected the maters who had not been seen that episode like Mike "Turbo" Bernardo and Ho Young "Star Warrior" Pak as the culprit and eventually put Star Warrior (who is the older brother of Superstar) on trial for it with Tiger Claw and Olympus acting as lawyers and Turbo as Judge. He was found not guilty after the glove Tracer clamed the mask ninja dropped did not fit (so they must acquit). It turns out the masked ninja was Warlock who had secretly joined the evil cult called Jukido and was trying to steal the Dragon Star
• Sanctuary has a particularly difficult one to solve. They do figure out who it is, but only the main characters survive until then.
• The story of the tail section survivors on Lost: Nathan is the Red Herring Mole. Goodwin is The Mole. Then there's Cindy and Libby, and we still don't know what was up with either of them. Prevailing fan speculation is that Libby was The Mole, too, but for a different organization.
• Haven has a nice twist on this. Some residents of Haven decide to throw Audrey a birthday party, since she's never had one. They decide to throw it on this nice old hotel out in the ocean on a small island with no cellphone reception. Well, long story short, the owner of the hotel had subtly dropped the suggestion that they should throw the party there. Turns out, the owner of the mansion is a chameleon-thing that kills people then turns into them, and he needs more people to change into. So one of the characters are no longer that character. Doesn't help that most of the people there are minor or new characters. Oh, and the ferry isn't coming back to get them until the end of the weekend, but there is a small boat that they ride away on.
  • Nathan's dad shoots a hole in the boat, stating that if the chameleon gets back to the mainland, he'll escape and vanish forever, living out his days killing more and more people. Oh, he's not the chameleon.
  • Since it's a birthday party, they decide to have everyone tell them what's in their gift, something chameleon wouldn't know. Here comes Nathan's turn. He says a blue sweater. Surprise: his present is actually a blue scarf. He had someone else buy the gift and comes to the conclusion that they must've thought that the scarf would've been a better gift than the sweater.
  • And the chameleon is... Audrey. Yes, the main character is the chameleon. When the chameleon transformed into her, he took her form, but she didn't die, so she had to lock her in a chest hidden away in the mansion. Nathan had recently discovered that he could feel Audrey, when he can't feel anything else. He figured out who the chameleon was he couldn't feel "Audrey". To confirm, he kissed Audrey, still felt nothing, pushed her back, and calmly shoots her in the chest, killing the chameleon.
• Doctor Who: "The Robots of Death". Unfortunately the title gives away a small but significant clue regarding the identity of the killer(s).
• Referenced by title, and played with, in the episode of Leverage, "The 10 Li'l Grifters Job". The Mark invites all his favorite enemies to a murder mystery dinner party. Right after announcing that someone is about to die, the lights go off, and someone actually kills him. Nathan, realizing that he would be the prime suspect, has to figure out who actually committed the murder... while simultaneously trying to convince the rest of the guests that it's actually all part of the event.
• "Murder at Moorstones Manor" is the Ripping Yarns take on this trope.
• Xena: Warrior Princess had an episode based on this premise, aptly called Ten Little Warlords.

Party Games

• Mafia style games often run into this, as the towns objective is to hunt out the mafia from their midst. Many is the game where a last lynch leaves two town players, or a last kill means the sole surviving mafia member.

Role Playing Games

• The The World of Darkness series is somewhat notorious for setting up this trope ad nauseum. Any time a vampire hosts a party, you can guarantee he's going to be dead by the end of the night.
• The 1E Ravenloft module's sequel, House on Gryphon Hill, features Strahd von Zarovich as The Mole within the Weathermay household, and the entire population of Mordentshire as its Ten Little Murder Victims ... with the added twist that not all the victims are being murdered: most are being possessed by Strahd's minions and turned into Moles as well.

Theater

• The Butler Did It, another comedy parody of this genre. A woman invites her favorite mystery authors to her mansion, and one by one they begin getting murdered. Characters start throwing in red herrings simply for the sake of having red herrings, and in the end the wacky maid reveals she is actually the killer-and not actually that wacky.
• The Mousetrap, also by Christie, did this, in which the characters were guests at a hotel trapped due to a snow storm.
• There is also a stage adaptation of And Then There Were None, also penned by Christie.
• Something's Afoot is a broad musical parody with the characters dying in increasingly absurd ways ranging from a man-eating vase to a pygmy hidden in a potted plant. As usual, there is a man and a woman left as the last survivors. While celebrating their survival, they accidentally drink the poisoned wine.
• In the play But Why Bump Off Barnaby?, Barnaby claims that one of the guests isn't who he seems, and even manages to write part of the person's name before dying. Of course, most characters have those three letters in their name.

Video Games

• Parodied in the Dark Brotherhood mission 'Whuddonit?' in The Elder Scrolls IV: Oblivion where the NPCs don't know you are the murderer, hired by the mansion owner to help him get revenge on them. You actually get a bonus if you manage to kill them all without anybody discovering that YOU are the killer.
• This is the premise of the amateur adventure video game 5 Days a Stranger (part one in the Chzo Mythos / John De Foe Quadrology series by Ben "Yahtzee" Croshaw): 5 people from different walks of life are lured into a house, one by one, and become trapped. Pretty soon they start dying. Each and every one of the five is a suspect, including the protagonist.
  • It turns out the culprit is a ghost, and has been possessing multiple different people - including the protagonist.
• That is actually the name of a map extension in Makai Kingdom
• The game Seven Noble Kinsmen has seven Shakespearean actors plus the player character, a theatre critic who ruined the actors' careers, invited to an isolated mansion/theatre by a mysterious host who never shows up. Of course, then people start dying off...
  • Interesting in that the murderer changes with each game play (the clues to his/her identity are also changed).
• This is the premise for a couple of roleplaying games using the BYOND engine.
  • Mitadake High. Except in high school.
  • Murder Mansion, too, complete with above-mentioned heavy storm.
  • Space Station 13 as well, set in space.
• The Point-And-click computer game The 7th Guest uses this as a base premise - with a twist. A mad toymaker lures guests into a house he built and makes them solve riddles. If they solve all of them, they'll get whatever they most desire. Unfortunately, these wishes either have an ironic twist - and that's only if the guest themself doesn't expire in the course of the game. Thing is, he only lured six people into the house. The seventh guest? A little boy who turns out to be you - and you were Dead All Along.
• This is the premise of the PC adventure game The Colonel's Bequest and its sequel The Dagger of Amon Ra. The first game takes place on an old plantation in 1920s New Orleans where the protagonist Laura Bow's friend has invited her to stay with her family, who have gathered to hear the old Colonel's will. Then people start dying, and you are forced to collect clues to try and figure out who killed who, and why. The second game takes place in a museum following a robbery, and one by one everyone inside starts getting bumped off. In both games it is up to the player to figure out just what is going on, and if you get it wrong you will get the bad ending and let the murderer escape, perhaps at the cost of your own life.
• Text adventure game Delightful Wallpaper is a version of this, with the PC (apparently invisible to the NPCs) placing various "intentions" around a mansion which drive the guests to kill each other.
• Mega Man Battle Network 2 has a portion spent like this. A group of Official Netbattlers, including the hero, Lan, and the rival, Chaud, are gathered in a castle for a meeting. It eventually turns out that not only was there a spy in their midst, the spy is the innocent-seeming Princess Pride, who faked being attacked early on. You learn this after both Lan and Chaud have already been left the only two suspects, and have fought to the Disney Death out of paranoia.
• The Garry's Mod gamemode Trouble in Terrorist Town is based on this, where there are "innocent" terrorists and "traitor" terrorists. The traitors are the murderers.
• In Nine Hours, Nine Persons, Nine Doors, the characters had been kidnapped by a mysterious person called Zero to play a 'Nonary Game.' But, some of the players know each other in a less-than-friendly context, and they aren't all able to go through the final door. You do the maths...

Webcomics

• In Jack, the titular grim reaper takes the souls of 5 people killed in an explosion, and leaves it to them to find out who planted the bomb. It's never made clear precisely why he does this, although escorting souls to Judgement must get a little dull, so maybe this is how he entertains himself.
  • Given the way the story was resolved it seemed likely that Jack was doing it in order to give some of them (particularly an individual in the group who had already suffered loss as Jack took someone he loved in a previous arc) a chance at last minute redemption and closure that if he just took them as is more would have gone to hell than actually did. Character development by that point had him doing what he could to help souls escape damnation and since he had already had 'monitors' following him around decided to put them to a positive use with their ability to create temporary zones like was done in that story.

Web Original

• Used in Kate Modern during the "Trouble in Paris" arc, in which the situation is complicated by several characters having their own secrets, and by the fact that, with one exception who ISN'T the mole, the characters are all friends and protagonists.
• Back when Neopets was intended for college students, there was the "Ski Lodge Murder Mystery", which consisted of (avatars of) staff members being stranded in a Ski Lodge in a snowstorm.

Western Animation

• Spider-Man and His Amazing Friends: In "Seven Little Superheroes," the Chameleon invites Spider-Man, Iceman, Firestar, Captain America, Doctor Strange, Namor the Sub-Mariner, and Shanna the She-Devil to an island where they are trapped by a forcefield and targeted one at a time. The episode's name even reflects the alternate name of the novel. Too bad Aunt May's puppy sneaks in and then becomes a Spanner in the Works, since she acts as an Evil-Detecting Dog...
• A Futurama episode, "Anthology of Interest I" features a story entitled "Dial L For Leela" that features this.
• The Scooby Doo episode "A Night of Fright is No Delight" (the one with the Confederate money.)
• An episode of Police Academy featured "Agatha Crusty" and "Ten Little Coppers".
• Transformers Animated has this in the Flash Back filled episode "Autoboot Camp". Wasp was framed, and the real mole went on to become the head of Autobot intelligence while Wasp slowly went insane. Way to go, Bumblebee.
• Family Guy took on this one in "And Then There Were Fewer". It was Diane Simmons in the dining room, the living room, the upstairs hallway, and an upstairs balcony with, respectively, the gun, the knife, and the Golden Globe.