Seamless Spontaneous Lie

A character(s) needs to come up with a lie or alibi, and it needs to be believable. What some people would do is come up with a broad yet believable story, and just hope that the interrogator doesn't Pull the Thread.

Not here! The liar here is simply so talented, that in the span of seconds, they can mentally Pull the Thread of their own lie, examine the fabric of their fabrication, and sew it back together. Or lucky enough that the words that come out of their mouth just happen to be as smooth as silk, and as impenetrable as a high thread count.

As such, the Seamless Spontaneous Lie is when someone is prompted to lie, and instantly comes up with a lie so incredibly detailed that there's little left to break or counter. The liar has lied so thoroughly that the interrogator could only reveal their lie if any of the following (or combination thereof) happens:
 * They (rightfully) assume that the liar must be lying.
 * Some outside detail, usually the most minor one possible, pokes a hole in the lie.
 * The liar comes clean.

For a greater challenge, several characters come up with the same lie or alibi, and present it in a way that is dependent on each other for specific facts or confirmation, but cannot coordinate it explicitly with each other. The lie is said and believed anyway, due to the confirmation of the high number of facts. This lie could either be done with all liars in person, or separated. The key is that they cannot actually coordinate it with each other, because then it wouldn't be spontaneous. Also, Rule of Funny or a strong relationship and understanding of each other keeps the lie coordinated.

Compare Blatant Lies and Snowball Lie, and Strange Minds Think Alike. Contrast Pull the Thread (or Stereo Fibbing for the plural version) and Hesitation Equals Dishonesty.

Anime and Manga

 * In One Piece, this is pulled not by the characters, but by way of Dub Induced Plot Hole. In the Japanese version of the Arlong Park Arc, Arlong gives Nami a knife to prove her loyalty by stabbing Usopp. She decides to fake it - she puts her hand in front of Usopp and stabs it, then telling Usopp to pretend to be hit and fall into the lake/pool. In the 4Kids version, through very cheap copy-pasting of scenes, Nami elaborates an impossibly convenient plan with Usopp while preparing to "stab" him: Usopp had to replace Nami's knife with a rubber knife (that he conveniently had with him, and that conveniently looked exactly the same as Arlong's knife), Nami hits him with it, and the rest of the scene is played more or less the same. And in the next episode, Nami's hand is injured, for absolutely no reason.
 * Kanade Suzutsuki from Mayo Chiki is a master of this trope. When Kureha, the sister of main character Jiro, asks about Kanade's butler Subaru being a guy or girl (because she had seen a "cross-dressing" Subaru with Jiro in the previous episode), she tells Kureha that Subaru is in fact a boy, and that she's dating Jiro, much to his surprise. Kureha immediately falls for both lies.
 * Later, in episode 7, while Subaru is on the beach in a bikini, Kureha runs into her, and initially thinks its Subaru (which she is). Kanade immediately points out that it's obviously a girl, and that said girl is Subaru's "cousin", Punyuru. Kureha once again falls for the lie.
 * At the end of episode 7, Nagare, Subaru's father and the butler for Kanade's dad, shows up at the beach to bring them home. At first both girls are a bit scared by his presence, but then immediately start questioning each other if they know who that guy is. Despite his pleas, both girls make it seem like he's really just a perverted stalker, and everyone immediately buys it. Cue Nagare looking confused as to why his daughter is doing this (mostly to keep him from blowing her cover since she can't be butler if anyone finds out she's not really a guy).
 * Kanade's lies are a little less effective on Usami however. When she tries to tell Usami about running away with Jiro to marry him on the beach, Usami sees right through it. Luckily Subaru approaches and overhears something which causes her to run away, prompting Jiro to chase after her. Usami tries to follow but Kanade stops her, and asks where she's spending the night at.
 * THE iDOLM@STER - The Producer (helped by Haruka) to Makoto when she's having a fit for being recognized as a Prince instead of a Princess.

Fan Fiction

 * In the Death Note fanfic Fever Dreams Light comes up with an elaborate one  L finds to his annoyance that he can't disprove it and the taskforce (though wary upon realizing that Light really is that manipulative) becomes convinced of his innocence and some even begin to see Light as a hero.

Film

 * In the Adam Sandler film Mr. Deeds, Babe Bennett rather poorly, but convincingly enough for the simpleton that is Longfellow Deeds, makes up a lengthy backstory of her childhood in "Little Winchestertonfieldville, Iowa". Some of the details are culled from pop culture, such as the physician "Dr. Pepper", and her neighbor and cat, Boo Radley and Atticus, respectively. Others are made up, such as a vivid depiction of her childhood house. Cementing this as airtight, Deeds actually takes her "home" as a gift, and her history is mistakenly (and hilariously) confirmed by the villagers. Even the house, which the current residents' father built with his own hands, existed. But Deeds is too in love to hear that little detail.
 * This is brilliantly used in The Usual Suspects. At the end we find out that  We never find out how much of it was actually true.

Literature

 * Murder on the Orient Express by Agatha Christie is centered on the murder of an American businessman on a train. As Poirot interrogates the passengers of the train. In the end,
 * A Song of Ice and Fire features so many talented Manipulative Bastards playing Xanatos Speed Chess that this happens quite frequently. One example that is surprising because it doesn't come from such a character is when Sansa tells Tyrion that she doesn't want to stay in the part of the castle he has chosen because, (the real reason being that it would interfere with her escape plans). Tyrion, who is quite a Guile Hero Magnificent Bastard in his own right, accepts this (very reasonable) explanation immediately, perhaps Foreshadowing that Sansa might not be totally out of her depth in this Crapsack World after all...
 * A less surprising example, given his nature is when  tells Catelyn that the dagger  . Since even Varys didn't know about the dagger in advance, one can reasonably assume that this lie was made up on the spot. Keep in mind that the events causing the War of the Five Kings were largely triggered by this single improvisation.
 * Anne Fine's book The Tulip Touch has this as one of Tulip's most notable characteristics. Being an abused child who craves attention, she frequently makes up implausible stories, but does it very well; the book's title refers to her habit of putting in that one little detail that always makes one wonder if she might be telling the truth just this once. She also fits this trope, because even when she is challenged, she is able to make up another, surprisingly plausible, explanation for the inconsistency.
 * A less surprising example, given his nature is when  tells Catelyn that the dagger  . Since even Varys didn't know about the dagger in advance, one can reasonably assume that this lie was made up on the spot. Keep in mind that the events causing the War of the Five Kings were largely triggered by this single improvisation.
 * Anne Fine's book The Tulip Touch has this as one of Tulip's most notable characteristics. Being an abused child who craves attention, she frequently makes up implausible stories, but does it very well; the book's title refers to her habit of putting in that one little detail that always makes one wonder if she might be telling the truth just this once. She also fits this trope, because even when she is challenged, she is able to make up another, surprisingly plausible, explanation for the inconsistency.

Live Action TV
"J.D.'s Narration: Now you're gonna lie here. Don't be too specific! J.D.: Since 1:42 yesterday afternoon. His wife did not want him to do it. She's beautiful, by the way - one green eye, one blue. She's from Luxembourg. They're both from Luxembourg. I believe they're, uh, Luxem... bourgian. Dr. Cox: Where in Luxembourg? I spent two weeks there. J.D.'s Narration: What are the odds? Just stay vague. J.D.: Uh, outside Mertert, near the German border. Dr. Cox: Ah. J.D.: They say what they miss most are those lazy summer afternoons on the Moselle River. J.D.'s Narration: You are channeling that seventh grade book report!"
 * A frequent tool of Scrubs.
 * One episode had a "seamless collaborative guy lie", to cover up their original one word lie being pulled. And it would've worked, too, if it weren't for Turk's meddling ass.
 * "My First Kill":

"Carla: Are you wearing boxers? J.D.: Yes, I am, Carla, because I know when Turk's sad, he likes me to come over in my boxers because he likes to call me his Honky Adonis, and that's what friends do. [Elliot and Carla look at each other and shrug.] J.D.'s Narration: They bought it? Are we that gay?"
 * "My Intern's Eyes", after Carla catches J.D. sneaking around the apartment he's no longer supposed to be living in:

"Barney: Here, let me demonstrate: I own a pony. Ask me a question. Marshall: Okay. Um, what color is your pony? Barney: Well, when I first got Dandelion she was a deep, chestnut brown, but, sadly, her stable is located near a chemical plant which contaminated the drinking water. So, over time, she's turned a sickly, grayish-white color and there's nothing the vet can do to fix her. Marshall: My God, I'm . . . that's horrible! Is Dandelion going to be okay? (beat) Okay, all right, you are good. Dandelion's not even sick, is she?"
 * On Arrested Development, Lucille uses a lie like this to cover up the fact that her children's Nana died, and she's been keeping the inheritance money they want for herself. By this point in their lives, the kids know not to believe her. This just makes Lindsay try even harder to find out what happened in order to get the money.
 * Barney from How I Met Your Mother sums this up pretty well: "If someone questions you, distract them from the original lie with more lies."


 * Skyler in Breaking Bad. When she needs to justify the large amount of cash her husband Walter earned from making meth, she spins a tale about Walt gambling that also explains the falling outs they had. It's so good Walter himself begins to listen in awe.
 * Walter does this fairly frequently as well. It starts out as clumsily handled Multitasked Conversations, but becomes increasingly complex.
 * On Unforgettable a murder suspect being interrogated by the cops, realizes that they have discovered that the murder scene was staged so he has to come up with a new story to distract the detectives. He uses the "take names from the bulletin board" technique to tell a believable story and the detectives spend a fair chunk of time chasing this red herring.
 * George on Seinfeld is usually terrible at lying, but he does have one shining moment when he sneaks an IQ test to supposed genius Elaine to take for him, then has to explain the food stains she got on it by concocting an elaborate story about how he went out the window to get some snacks.

Theater

 * Neil Simon's Rumors has a ridiculous one at the end. Lenny (who's been posing as an incapacitated friend) suddenly pops up to explain to the police what happened to get them off their backs. This monologue goes on for about four pages, all making a reasonable amount of sense. It seems like he made this up on the spot, much to everyone else's shock.

Video Games

 * Very common in Ace Attorney, where characters who are caught out on their lies often come up with entirely different, equally detailed stories within very little time. Of course, due to the nature of the game, these are always found out eventually.
 * Probably the best example is from the third game. For the last bit of testimony, this witness/suspect rapidly puts together a series of "patches" for the various holes in the story. All of them hold up surprisingly well to scrutiny...

Western Animation

 * Roger of American Dad frequently manages to utilise one of these (given his multiple dress up personas, he is likely come to be accustomed to it).
 * Stan actually labels it something of an endearing trademark for him when he seemingly reads off a number of redemptions he vows to acomplish off a sheet of paper (it's all just a spontaneous lie, the paper is blank).