Bluffing the Imposter in Literature.
- In Kir Bulychev's Alice, Girl from the Future series it happens very often, considering that Alice's Arch-Enemy is a shapeshifter. In The Jewelry Box of the Pirate's Mother, Alice encounters someone looking like her friend Rrrr, only she had just helped the latter flee, bandaged and bleeding. Pretending to be happy, she reminds the false Rrrr that she had to come to Brastak (his planet) from Earth via another planet (while in reality she flew straight there from the planet Penelope), tells him that on Earth it's raining mushrooms, and asks him if he remembers how they met on Pataliputra and played in the snow (that planet has tropical climate even in the polar regions). When he doesn't react to any of it, she is left with no doubt that it's an impostor. Subverted, since she gets carried away so much with thinking up absurdities, the impostor also realizes she doesn't believe him.
- Animorphs:
- When David morphs into Marco, Rachel taunts the real Marco with "You know you're a toad, right?" and Cassie asks him to describe how it felt when they morphed trout. They know it's Marco because he answers sarcastically ("Kiss me and I'll become a prince," and "The cracker crumb coating chafed," respectively).
- In another book, a Controller says the word "Andalite!" loudly to a person he suspects to be an "Andalite bandit" in human morph. In reality, he's as close to being right as you can be, as the person in question is Cassie in Rachel morph. But he's satisfied when, without missing a beat, Cassie/Rachel immediately replies as if he had just said the words "and a light".
- Marco also does this after his dad discovers Z-space, trying to see if his dad's a controller by pointing out that the trip his dad wants to take would mean they'd be gone more than three days, the amount of time a Yeerk can go between feedings.
- J. R. R. Tolkien's Beren and Lúthien:
- When Sauron sees twelve Orcs to march very, very quickly past his tower, without coming to report, he grows suspicious and commands that they are intercepted and brought before him. Sauron then asks their names and their captain's, and they answer they are under Boldog's command. Now certain that he is dealing with Elves disguised as Orcs, Sauron replies Boldog was slain some time ago.
- When Beren and Lúthien sneak into Angband, disguised as a werewolf and a vampire, Morgoth spots the latter and asks who she is. Lúthien answers she is Sauron's courier, Thuringwethil. Morgoth replies Sauron's courier has just left, and she better takes her disguise off...or else.
- The Curse Workers: In White Cat, Cassel casually asks his brother Barron if he remembers certain incidents from their childhood, and Barron says he does... except the incidents are things Cassel made up, or that happened to someone else. In this case, though, Barron isn't an impostor; he's suffering from memory loss and trying to cover it up because he's a memory worker suffering the magical backlash from repeatedly altering Cassel's memories.
- Dirk Pitt Adventures: In Iceberg, hero Dirk Pitt meets scientist/businesswoman Kristi Fyrie at a dinner. From the start, Pitt thinks something is off as Kristi talks of having spent years in the South American jungles but Pitt notes her skin is nowhere tan enough for that. He talks of wanting a steak that's basically an echidna seaweed and she agrees it's a delicious dish in New Guinea. Later in the book, Pitt explains it to an ally who doesn't grasp it at first.Pitt: How would you react if I said I just barbecued a New York cut steak wrapped in porcupine quills?
Ally: I'd say something.
Pitt: You get the idea.- A slight subversion in that it turns out Pitt believed Kristi was an imposter posing as the sister of the late Krisjan Frye; in reality, she is Frye having secretly undergone a sex change.
- Discworld:
- Carpe Jugulum: A vampire tries to get Magrat to open a door by pretending to be Nanny Ogg. Magrat demands that "Nanny" first tell the joke about the old woman, the priest, and the rhinoceros. The vampire tries to protest that this isn't the time for that — proving it's an impostor, since the real Nanny Ogg always has time for a dirty joke. It's not pointed out, but longtime readers might also catch the fact that the vampire had exclaimed "lawks!", a stereotypical old-lady cry which the elder witches only resort to when they're pretending to be harmless.
- Feet of Clay: Dorfl the golem comes into the Watch building partway through the book and confesses to committing the crime they had been investigating. Carrot, suspecting (correctly) that Dorfl is turning himself in to protect the real criminal, tests him by including incorrect details:Carrot: You killed the priest as well?
Dorfl: Yes.
Carrot: You beat him to death with an iron bar?*
Dorfl: Yes. - The Klatchians in Jingo don't know exactly what Sgt. Colon is up to (they think he's a spy from somewhere else doing a really bad impersonation of an Ankh-Morpork spy) but they do know that he can get out of his depth on a wet pavement, so they tell him the Klatchian army has gone to "En al Sams la Laisa," which translates to The Place Where the Sun Shineth Not. Vetinari is unimpressed when Colon reports this.
- In Robert A. Heinlein's Double Star, a disguised actor impersonating a politician meets with the Emperor of the Solar System. The Emperor insists that he play with his toy trains, which the actor dutifully does. The Emperor then asks him who he really is, because all the past times he had met with the politician and asked him to play with the trains the politician had refused and teased him about having such a childish hobby — it was a sort of game between them. It was an interesting play on this trope, as the actor's impersonation was so flawless that the Emperor hadn't really been all that suspicious until that point.
- In Aaron Allston's Galatea in 2-D, when Roger suspects the false Donna, he asks if Elsie's at David's, rather than Dylan's.
- Harry Potter
- In Half-Blood Prince
- The Ministry advises people to ask this kind of question to make sure a Death Eater isn't impersonating your friend. Harry quickly figures out for himself that when magical compulsion is one of the favorite tools of the bad guys, this sort of thing is the barest of bare-bones contingencies. Dumbledore states that he agrees with him.
- Arthur Weasley comes home from the Ministry and passes Molly's challenge at the door. When she goes to open it, he grabs it and pulls the door shut again so he can challenge her. Afterwards, Molly comments that it's silly, since anyone impersonating Arthur could easily torture the question and response out of him. He agrees with her, but says that they should do it to set an example.
- In Deathly Hallows, members of the Order of the Phoenix start doing this to each other. There is the slight variant that they don't agree on what questions to ask beforehand, instead just asking about random moments in their past, making the system more secure.
- In Half-Blood Prince
- Hardy Boys: In the Super Mystery "Stage Fright" the brothers are on the receiving end of this from a suspicious theater employee.Damien: So what shows have you done?
Joe: Uhh. Bye Bye Birdie. The Music Man, you know, the usual.
Damien: So you guys are big Sondheim fans? Me too.
Joe: We love him. Now if you don't mind, I have to-
Damien: That's funny. Because none of those shows are by Sondheim. - In Kurt Steel's The Imposter, the president of an aircraft company, after discovering the dead body of a double who was sent to impersonate him in a Nazi plot but ran afoul of an entirely separate Nazi plot to assassinate said president, decided to pretend to be the double in an attempt to flush out both sets of enemy agents, but was revealed when one of the dead man's more suspicious associates made some comments about things which had never happened.
- Appears in The Light Bearer, a historical-fiction story about the Roman conquest of Germania. Germanic chief Baldemar reveals an imposter to be a foreign spy by asking him if a famous local woman has recovered from an illness, to which he replies that she has — she actually died the previous year.
- Isaac Asimov's "Little Lost Robot": When one of the NS-2 robots with a modified version of the Three Laws tries to hide in a group of physically identical NS-2 robots with unmodified Three Laws, it has to convincingly act as if it were an unmodified NS-2 robot. Dr Calvin designs three tests to flush out the imposter robot:
- The lost robot foils the first test because, while it doesn't have to rescue a human in danger, it can choose to do so as quickly as the other robots are compelled to by the First Law.
- Dr Calvin puts the robots in a situation where trying to rescue a human would (as far as they know) destroy them (prohibited by the Third Law unless trumped by the First or Second). Indeed, the lost robot does not try to rescue the human — but has cleverly convinced the other robots not to try either (that they'd be destroyed before succeeding becomes an argument to ignore the First Law).
- In the third attempt, Dr Calvin puts the robots in the first situation again — but the unmodified robots think it's the second, and stay still; the lost robot had been recently trained to recognize the difference between certain radiation wavelengths while the unmodified robots hadn't.
- Also shows up in The Lost World (1912), when Malone is trying to gain Professor Challenger's trust by pretending to be a fellow scientist, Challenger quizzes him on various scientific terms, all of which Malone claims to be familiar with. Challenger then informs him that he had been speaking gibberish and tackles him out the door.
- In Lawrence Block's Me Tanner, You Jane Evan, after spending several days with a man claiming to be fellow agent Sam Bowman (whom Evan had never met), becomes suspicious and states in casual conversation that the chief of their agency is a by-the-book fellow who wears a plaid hat. "Bowman" doesn't contradict either "fact".
- In Rise of the Elgen, Hatch brings Tara to visit Michael's captive mother with him, claiming she's Michael's friend Taylor and having her praise the Elgen. Mrs. Vey bluffs Tara by asking about a watch Taylor gave Michael (which was actually a gift from his mother) and casually saying that her dad is a schoolteacher. Tara fails to catch either mistake, giving herself away.
- In a Nancy Drew book, Nancy has become suspicious of a young man claiming to be the long-lost son of the wealthiest man in town. (The man was presumed dead in an avalanche during a trip to Switzerland but has returned several years later, claiming to have been recuperating in a hospital all this time). While initially charming everyone, he still makes several mistakes — buying his housekeeper a chocolate cake for her birthday when he should know that she's allergic, as she once had a severe reaction in front of him. Nancy finally trips him up by gushing about his 18th birthday party (the last one he had before vanishing), mentioning how cool his "giant purple and white football cake" was. The man enthusiastically agrees — until Nancy coldly informs that that's NOT the kind of cake that was served.
- Nancy also does this to Beth's boyfriend Alan in one of the Case Files stories when Beth goes missing, and she suspects Alan knows more than he's letting on. She asks if Beth took a specific type of medication. When Alan says yes, Nancy realises he's bullshitting because Beth is allergic to said medication, and taking it could kill her. Alan is forced to come clean.
- In John Barnes's One for the Morning Glory, the Duke challenges Sir John to name Calliope's birthmark on her thigh. Sir John sputters. Given that with Sir John's reputation, any imposter would have improvised because of course Sir John would have known.
- The Otherworld: In Haunted, Lucas asks "Jaime" if she wants Indian food, confirming Eve's claim that she's been possessed by a demon ghost.
- This is how, in an early arc of Perry Rhodan, Atlan discovers that the eponymous protagonist has been replaced by a doppleganger — specifically, his first son who has undergone a Face–Heel Turn. The impostor has most of the original's current knowledge due to his allies telepathically interrogating the former before setting the plot into motion, but Rhodan managed to slip in just enough misinformation about his initial clashes with Atlan for the latter to catch on once the subject comes up. (In their first duel in that museum on Venus, they fought with broadswords, not smallswords, and the imposter then failing to recognize a silly little rhyme that had special meaning for them both after a long, wearying chase on the planet Hellgate cinched it.)
- In one of Robert Asprin's Phule's Company novels, a Space Legion soldier trying to prove his identity is asked "Who led the Galactic League in free flies last season?" Not only can he not come up with the player's name, he misidentifies the sport—and his comrades conclude that it's really him, because he's known to be completely ignorant about sports.
- In Kerry Greenwood's "Raisins and Almonds", Phryne Fisher discovers that a man who has gone to great lengths to masquerade as a Jew is not actually Jewish by the fact that he cannot sing the lullaby "Rozhinkes mit Mandlen" ("Raisins and Almonds"). However, this would not have worked in real life. The lullaby is written in Yiddish, a language based on Middle High German spoken by central and Eastern European Jews. The group of Jews involved in the story were from a community where their Judaic language would have been Ladino, an entirely different language based on Spanish.
- In one of the Ranger's Apprentice books, Will is in disguise as a minstrel. The lord of the castle he's visiting asks if his instrument was made by the master luthier Gilperon, and Will says no. Later the lord informs him that the luthier's name is actually Gilet, which a real musician would have known.
- The Reynard Cycle: Reynard enters into one of these with a shapeshifter who has done its research during Reynard the Fox. The one thing it fails to mimic is Reynard's complete contempt for authority, even in the face of death.
- Rhythm of War (fourth book of The Stormlight Archive): Shallan suspects that one of her Lightweaver apprentices is secretly a spy for the Ghostbloods, but isn't sure which of them to suspect. So while conversing with the suspects, she mentions that she's seen a corrupted spren (telling each of them that it was a different species of spren) and asks them to keep it a secret for now. Sure enough, during her own negotiations with Mraize, he mentions the corrupted spren. As it turns out, the spy was actually reporting to someone entirely different, a friend who was worried about Shallan. They were unaware that Mraize could listen in on those conversations.
- In The Savage Damsel and the Dwarf, the title characters are staying with a group of knights, and the dwarf mentions that he used to serve Sir Gaheris. One of the knights asks casually if Sir Gaheris is still as skilled a swordsman as ever. The dwarf who is actually Sir Gaheris under an enchantress' curse passes the test when he responds that the knight must be thinking of someone else, since Sir Gaheris is a notoriously abysmal swordsman.
- It also shows up in Arthur Conan Doyle's Sherlock Holmes story The Adventure of the Three Garridebs. When a man claiming to be an American lawyer recently arrived in London calls on Holmes, Sherlock first asks whether the American had placed an ad in the "agony columns" and is assured that he did, then when the 'American' says he's from Kansas, Holmes mentions an old correspondent of his, Dr Lysander Starr, who was "mayor of Topeka in 1890." The 'American' assures him that Dr Starr's memory is still honored in Kansas. After he's left, Holmes assures Watson that he's not what he claims - there was no ad in the agony columns and "Dr Lysander Starr" is completely fictional.
- In the fourth book of A Song of Ice and Fire, A Feast for Crows, Sam Tarly arrives at the city port of Oldtown where he hears from an Oldtown harbour offical that the Ironborn attacking the coastline of the Reach seized a Tyroshi ship, killed its crew, then dyed their hair all different colours in the fashion of Tyrosh, hoping to slip into Oldtown in disguise and then cause chaos to allow an attack on the city. Unfortunately, the captain of one of the ships in Oldtown's harbour was married to a Tyroshi woman, and when none of the "Tyroshi" crewman answered him when he hailed them in their native language, the captain realised something was wrong and raised the alarm.
- In the Tom Swift book Monster Machine in the aftermath of the main cast being kidnapped Tom and Rick are trying to rescue their girlfriends from a room when a computer sensor tells them it's filled with poison gas. They ask the girls to answer specific (trick) questions which they are unable to do. A little later, when they find the real girls (wearing gas masks) they ask the same questions just to make sure and this time they know the right answers.Tom: Mandy, tell me what color bathing suit you wore on our date last Friday.
Mandy: Tom, what are you talking about? Nobody wears a bathing suit to the movies, not even in California! - In Vladimir Vasilyev's The Treasure of the Kapitana, an Albionian (British) captain is seeking to hire a Tauridan (Crimean) pilot to help him sail the treacherous waters of the Euxine (Black) Sea. While the local pilots (called "shtarkhs") use more magic than learning to navigate the sea, Ralph also has a piloting degree from the Southampton Naval Academy. He shows his diploma to the captain, who immediately asks how his good friend the chancellor of the academy is doing, seemingly forgetting his name. Ralph helpfully supplies the name and, when the captain asks how the chancellor's wooden leg is feeling, calmly corrects him that, when Ralph last saw the chancellor, he had two good legs but only one eye.
- Warhammer 40,000: Used in Dan Abnett's third Eisenhorn book, Hereticus. Eisenhorn spots an imposter posing as a trusted member of his retinue by saying their situation reminded him of the tight spot they'd been in fighting Beldame Sadia on Eechan. The imposter agrees, alerting Eisenhorn (and any particularly astute readers) to the trick — they'd actually fought Sadia on Lethe Eleven.
- In Worm, the fact of Regent's People Puppets power leads to Weld subjecting Shadow Stalker to one when she shows up with several members of the Undersiders in custody. Regent was indeed puppeting Shadow Stalker; he and Tattletale correctly realize that it wasn't Kid Win that Shadow Stalker got in a fight with earlier that day, but they incorrectly guess Clockblocker rather than Vista, alerting Weld that Shadow Stalker is being puppeted.
