A trope mostly in comedic works where, when given multiple explanations for an event, the oddest one is most likely to be true. The inverse of Occam's Razor. As such, it can be summarized as "When you hear hoofbeats, think zombie zebras from outer space, not horses."note The name is a take off of Occam's Razor, combined with Arkham, which refers to the fictional Massachusetts town in the works of H. P. Lovecraft, and also to the fictional insane asylum in Batman comic books. Thus, the term "Arkham" is closely tied to the idea of madness or surprise.
Often used as a form of Bait-and-Switch. When provided with a sufficiently improbable-sounding story, the audience, expecting Occam's Razor, writes it off only to be surprised that the outlandish possibility was correct.
See also: Never the Obvious Suspect, Infallible Babble, Cassandra Truth. Often overlaps with The Cuckoolander Was Right, Accidental Truth, or Refuge in Audacity. May be the basis of a Brick Joke. Compare Impossibly Mundane Explanation, where an explanation floated by a character is dismissed for being too mundane, and Aluminum Christmas Trees, which is an example of how this can happen in real life.
- Batman: Some of The Riddler's riddles work this way. For a relatively grounded example, his first-ever crime used the clue "banquet", sending Batman and the police to a charity dinner. The real and much less conventional meaning of the clue was that the Riddler had flooded a bank vault — gotten a "bank wet" — to defeat its pressure-sensitive locking mechanism and was looting it in scuba gear.
- My Little Pony: Friendship is Magic (IDW): In "Copycats", when discussing Fluttershy's odd behavior, Twilight tries to argue against jumping to the worst possible conclusions, because surely Fluttershy's behavior is more likely to be due to overwork and overstress than some random magical effect they have no evidence of having taken over her mind... before conceding that yeah, it's probably magic.
Twilight Sparkle: What's easier to believe? That she's just tired and acting strange, or that she's under the influence of some weird magical spell?
(Everyone looks at her incredulously with Spike giving an Aside Glance)
Twilight Sparkle: Magical spell, you're right.
- What the Cat Dragged In: Due to the fact that all methods of recognition (from simply looking at them in person to the use of advanced government recognition software) fail to decipher Ladybug and Chat Noir's true identities (even simple things like their age-range), as well as the unlikelihood of Ladybug and Chat Noir's identities remaining a secret despite public security technology like cameras, S.H.I.E.L.D. has reluctantly come to the conclusion that they operate on a magical glamour.
- The Adventures of Baron Munchausen: In one scene, the heroes have been imprisoned by the King of the Moon. The Queen of the Moon — who, like her husband, has a detachable head — comes to their rescue in head-form. She giggles and moans constantly as she tries to unlock the cage, and Sally asks the Baron what she's laughing about. The Baron tells the little girl, "Um, her body is with the King, and he is, uh... tickling her feet." Cut to the royal chamber where the King is in bed with the Queen's body, and he is in fact... tickling her feet!
- Girl, Interrupted: Early in the movie, the main character is told that she may have to have therapy with "Dr. Wick". "Wick's a girl." the other girls joke. "Wick's a chick." It's far from clear whether they are being literal, or simply demeaning a physician they don't like, so it comes as something as a surprise when we meet the man himself, and he turns out to be — Vanessa Redgrave.
- Hook: The first time we meet Tootles, he's searching frantically for something. When Peter asks him what he's doing, he says, "I've lost my marbles!" Which Peter of course interprets metaphorically, thinking that Tootle's has gone insane. Much later in the movie, Peter learns that Tootles used to be a Lost Boy, and that he left his (quite literal) marbles behind in Neverland.
- True Grit: Mattie makes repeated references to her lawyer "J. Noble Daggett". She pulls out his name every time she wants something done, threatening legal action against those who get in her way. After about the fifth time, Rooster and LeBoeuf express skepticism as to whether this "Lawyer Daggett" even exists, and the audience might be inclined to agree with them. But at the end of the film a little man in glasses walks into Rooster's room, and introduces himself as lawyer Daggett himself!
- The Boxcar Children: The real culprit of most later installments is invariably whichever suspect is not actually suspected by the title heroes.
- Discworld: In Guards! Guards!, Dibbler claims his anti-dragon cream is manufactured by saffron-wearing monks in the high mountains, but Captain Vimes brushes it off as Dibbler's standard false advertising. At the end of the book, we find some monks loading up a yak with bottles of herbal cream bound for Ankh-Morpork, and one of them wonders what the hell Dibbler does with them.
- Easy Avenue: The backstory has it that Mrs. O'Driscoll's husband went "missing" in the war. All the characters understand that "missing" means "dead", but Mrs. O'Driscoll sometimes indulges in fantasies about him surviving and living it up on some tropical island. This sounds wildly improbable until the very end of the book when the characters are having a picnic and Mr. O'Driscoll suddenly turns up!
- G. K. Chesterton uses this in several works. Justified by at least one character. As he puts it, "This priest tells me that an Irishman can appeal to a God I know nothing about to avenge him according to some Higher Law I also know nothing about. Well, there's nothing for me to say except that I know nothing about it. But you ask me to disbelieve in the world as it appears to my own five wits."
- In Harry Potter, it's frequently suggested, half-jokingly, that the position of Defence Against the Dark Arts teacher must be cursed since no DADA professor ever lasts more than one school year. The reader isn't invited to take this very seriously until Book 6 when Dumbledore reveals that it actually was cursed by Voldemort.
- Implied Trope: Dumbledore never actually confirmed that the position was cursed (as he wasn't certain himself), but he does reveal that the problems with the position started immediately after he turned down Voldemort for the job. Also technically a subversion, as now, the explanation that the position is cursed is no longer particularly outlandish.
- In The Hitchhiker's Guide to the Galaxy, Arthur muses that the universe must be run by madmen. In a later book we find out that one isolated madman makes all the important decisions in the universe.
- A Lion On Tharthee: Junior mocks the group of people who thought intelligent life only needed a "big brain" to evolve, saying "Occam's Razor was dulling itself trying to shave a pickle."
- In The Long Dark Tea-Time of the Soul, the protagonist inverts Sherlock Holmes' famous quote, saying "When you have eliminated all which is improbable, then whatever remains, however impossible, must be the truth." This is the person who owns an I Ching calculator that returns any answer higher than four as "a suffusion of yellow", practices zen driving (rather than just drive where you want to, find another driver that seems to know where they are going, and follow them), and claims that the perpetrator of a particularly grisly closed room murder got out by travelling to another dimension. He is entirely correct about the last one.
- One Rainy Night: An explanation for the black rain that turns everyone it touches into homicidal maniacs is given very early on, when a character half-jokingly says that it's Voodoo magic. Cut to the end of the book and it turns out that the rain is being caused by a naked old guy invoking a Voodoo curse on the town by spitting black ink onto a canvas.
- Ancient Aliens and many similar shows bend themselves backwards twice to prove everything that ever happened in the history of the world was, without doubt, done directly by or at least connected to aliens.
- Arrested Development runs on this trope, usually in form of simple statements that end up being correct in an utterly bizarre way.
- The pilot has a character seeing a group of gays protesting a yacht club and comments "I have that same top." Turns out it was actually her top and her husband had mistaken the party she was as a pirate-themed party due to an offhand comment, then accidentally got onto a bus with a group of gay protesters (whom he thought were dressed similar to pirates) and ended up protesting the party he was supposed to be attending.
- Toyed with, with a doctor who was always incorrectly literal. Telling the family "He's all right" when in fact he was saying he's "all right" because a seal bit off and ate his left hand.
- And of course, "there's always money in the banana stand." There was literally $100,000 in cash hidden in the banana stand.
- Brooklyn Nine-Nine: In "Jake & Amy", a bomb threat is called in, ruining Jake and Amy's wedding. Naturally, Jake says it's just an idle threat to ruin the day (since it would be counter productive to actually warn them that a bomb was going to go off at a particular time), but the bomb-disposal technician (who is openly in love with Amy and wants to break up the wedding himself) says something along the lines of "well, what if the bomber's daughter found blueprints and felt guilty and called to warn you?" True to the trope, this is exactly what happened.
- Buffy the Vampire Slayer: Used as part of how the Weirdness Censor is justified on early seasons, where the police (who know the truth about the town's vampire problem) have little trouble convincing most people that the vampires are just PCP addicts. As Oz points out when he's told the real story, the vampire explanation actually makes more sense.
- In a fourth-season episode, Anya talks hypothetically (and comically) about the possibility of a world made entirely of shrimp. Four years later, on Angel, Illyria reveals that she has visited just such a world.
- In the Musical Episode, Giles's first theory as to what is causing the outbreak of deadly singing and dancing is "a dancing demon", which he immediately dismisses. Of course, he's right.
- Community: Double-subverted when the study group cannot work out what happened to Annie's missing pen. Unwilling to believe any of the group stole it, they agree to believe Troy's manufactured story that a ghost took it. In fact, it was Troy's escaped pet monkey.
- House: Often played non-comedically. In medical jargon, an unexpected diagnosis is referred to as a "zebra". Justified, in this case, because dealing with the zebra cases is the entire reason for House's department existing. They only get the weird cases that the regular doctors can't figure out, similar to how Sherlock Holmes probably didn't deal with many conventional crimes that Scotland Yard was able to deal with on their own.
- How I Met Your Mother: In one episode, the gang is arguing about who was the most "badass" as a kid. All of their tales of youthful rebellion are eventually proven false, except for Team Mom (and literal mom) and kindergarten teacher Lily, who painted a picture of herself as basically an Expy of Omar Little from The Wire. Naturally, at the end of the episode this is proven true.
- Monk has effectively made cases against people who were in outer space or even in a coma at the time of the murder. It's pretty much guaranteed that, as he only works the insane cases that no-one else can figure out, the murderer will always be the least likely suspect with an air-tight alibi.
- Psych: One episode has a body found in the ocean with what looks like large teethmarks. While the police posit ideas like a shark, or an unusual knife, "psychic" detective Shawn immediately says a dinosaur did it. No prize for guessing who was right. When he explains his logic after the Cold Opening, it actually makes sense. The fact that it's completely ridiculous is what throws people off, and the chain of events that led to said injuries and death is convoluted and bizarre, but his initial deduction was spot-on and perfectly reasonable.
- Scrubs: In "My Balancing Act", when JD (who recently watched a relevant TV program) suggests a patient may be infected with a flesh-eating bacteria rather than a simple case of cellulitis, Cox immediately rejects this, explains the concept of Occam's Razor ("Think horses, not zebras"). JD, however, turns out to be right. Apart from this instance, however, the trope is usually averted.
- The Young Ones made it something of a Running Gag for Rick to sarcastically state that Mike was up to some ridiculous money-making scheme (e.g. turning Rick's bedroom into a roller disco), which would turn out to be right.
- Fortean Times, a magazine dedicated to the investigation of strange phenomena, takes the sensible point of view that Occam's Razor is generally the right approach to take in evaluating evidence. But FT is keen to point out that Arkham's Razor should not be scorned and may, in some circumstances at least, be more entertaining — and maybe even potentially useful. If you deal with strange things where all the usual bets are off, you need a different approach.
- Kid Icarus: Uprising plays with this in the next to last stage. When fighting what appears to be Magnus and Dark Lord Gaol, Pit and Palutena suspect that Dyntos, god of the forge, had made fake copies of them, like he'd done with almost every other boss in the game. It turns out that he just invited the real ones over.
- Red vs. Blue plays with this. At one point the Reds try to figure out why Lopez disappeared, then later the Warthog went nuts and started trying to kill Sarge. Donut actually hits on the rather bizarre correct answer: Church got killed, then his ghost possessed Lopez to use for a body, then the Blues accidentally triggered the Hog's remote control while looking for Lopez's "fix stuff" function. But the other Reds think Sarge's brainwashing beam idea is more likely, and they'd rejected that one out of hand for the Mundane Solution that the Blues reprogrammed Lopez.
- RWBY: Emerald and Neo . The audience knew little beforehand about either character, but knew that Neo could create "illusions" somehow, that had previously been dispelled by Yang shattering them while the real Neo got away. She was later seen with an altered appearance and seems to change her eye color repeatedly just to do so. Pressing the point that she could alter what people see was her various disguises taken during the Vytal Tournament, with her pink and brown eyes being the only hint to her identity. Thus, when presented with clear situations where someone was messing with what a character sees and hears, fans assumed it was Neo. There were the odd fans that insisted it was Mercury or more likely Emerald who had the illusion power (mainly due to one of the biggest uses of said illusions occurred to a character who was hunting Emerald down and couldn't find her), but they were promptly shouted down and considered ignorant of canon. It later turned out that Emerald was the person crafting illusions, though Neo still retains the strange reality-altering powers she had before, which have yet to be explained.
- Questionable Content: This shows up a couple of times.
- In one strip, Marten and his girlfriend Dora take a long lunch, and return with Marten wearing some of Dora's clothes. Their friends immediately assume that they had done something naughty, but Marten claimed that they had been ambushed by Shaolin Monks and spilled spaghetti sauce on his clothes and needed to change at Dora's. Everyone laughs it off, but a few strips later he is proven correct when a battered monk arrives at the coffee shop and recognizes Marten.
- Also occurs in the explanation for Steve's infrequent appearances for a long stretch of the comic. The two possible explanations were "he got drunk and dicked around for a while" or "he became a secret agent and blew up an island," and it was implied that not even he knew for sure which was true. Until later, when he ran across The Baroness from his story.
- Unsurprisingly lampshaded in The Order of the Stick: When the rest of the cast jump to a wild conclusion regarding the parentage of a child, Only Sane Man V points out that they have nowhere near enough evidence to reach said conclusion... but given their past experience, that probably means they're right anyway.
- The Adventures of Jimmy Neutron: Boy Genius: In one episode, Sheen's action figure is stolen. After ruling out all the other suspects, Jimmy quotes the original Sherlock story when he realizes the true thief must be the one they first ignored due to being too ridiculous: a bunch of squirrels.
- Ben 10: Omniverse: In "Bengeance is Mine" Ben is convinced a man named Bill Gacks is really Vilgax in disguise despite Rook's scanner confirming he isn't because it's too much of a coincidence that he closely resembles Vilgax, has a similar sounding name and just happens to be around whenever a holographic projection of Vilgax appears. In this case, Ben is wrong.
- Futurama: In "A Pharaoh to Remember", the characters travel to O'Cyrus IV, which strongly resembles Ancient Egypt. When Fry finds out that its inhabitants visited Egypt thousands of years ago, he concludes that the theories were right... but is quickly told that the aliens took their culture from the Egyptians, who taught them pyramid-building. This itself is subverted seasons later in "That Darn Katz!", which reveals that the pyramids were in fact built by a different alien race, meaning that the O'Cyrians got the knowledge thirdhand.
- Peanuts: In A Charlie Brown Christmas, while rehearsing for a Christmas pageant, Sally talks about waiting for Harold Angel to sing. Charlie Brown thinks this is just the standard Mondegreen for "Hark the Herald Angels Sing" until a kid named Harold Angel shows up looking for Sally.
- A Pup Named Scooby-Doo: Used in almost every episode. During The Summation, every suspect is listed... and the one character who isn't listed for whatever reason (too unlikely, had an alibi, or just plain the writers didn't feel like including them) is invariably the culprit.
- Scooby-Doo! Mystery Incorporated: The real culprit behind the mask is usually someone who is only seen once or has little to no connection to the subject the Mystery Inc. are investigating. In fact, one of the villains was seen earlier in a mascot outfit for only a few seconds.
- The Simpsons: In "Who Shot Mr. Burns?", the family watches the news report that Smithers has been found innocent, and Marge comments that it's never the most likely suspect. Lisa counters that actually, in 95% of cases it IS the most likely suspect, and the rest of the time it's just some random person with no motive at all. Incidentally, the actual culprit fits this trope nicely: it was baby Maggie, of all people.
- SpongeBob SquarePants: In "Bubble Buddy", SpongeBob makes a bubble mannequin and acts as if he were alive. The others get tired of SpongeBob's antics and try to pop the bubble, but just as they are about to Bubble Buddy suddenly comes to life and stops them, confirming that he was alive all along.
- Teen Titans Go!: Rule of Funny dictates that the silliest explanation for something invariably turns out to be correct. Usually it's Starfire's proposal, but sometimes others are the lead.