[[quoteright:248: http://static.tvtropes.org/pmwiki/pub/images/lietomemt9.jpg]]
[[caption-width-right:248:You're just telling porkies, aren't ya?]]

->'''Cal:''' But a scientist's job is to verify, right?
->'''Emily:''' You never trust anyone, do you? You know, that's why you'll always be alone.
-->--"Exposed"

Dr. Cal Lightman is a LivingLieDetector, able to calculate human honesty through facial expressions - called [[http://en.wikipedia.org/wiki/Micro-expression Micro Expressions]] - and body language. The pioneer of this field, he operates his own business, working with federal and private clients to solve criminal and civil cases. A case of TruthInTelevision (well, somewhat), as the show is based on the science of Paul Ekman.

Lightman is joined by a team of [[OddlySmallOrganization three other analysts]]. Dr. Gillian Foster is Lightman's close friend and the other senior staff member. She usually heads up another investigation while Lightman is busy on a separate case. Ria Torres is a "natural" deception-detector. Lightman found her as a security agent at the airport. Rounding out the band is Eli Loker, an utterly shameless flirt committed to [[WillNotTellALie 100% honesty]][[note]]His radical honesty disappears quickly in season 1[[/note]]. Lightman's precocious teenage daughter is part of the cast as well.

The usual format of the show follows the team around as they pursue [[TwoLinesNoWaiting two different cases]], typically one criminal and one brought to them by a private client. Though their research into microexpressions can't be used in court as evidence, it provides a start for prosecutors and companies in ferreting out the truth.

The show stars TimRoth as Dr. Lightman. That's right, [[Film/ReservoirDogs Mr. Orange]] knows when you're lying.

It seems similar on the surface to ''TheMentalist'': a smart guy that can tell if you're lying, and who's fond of the BatmanGambit, works to solve crimes. There's the wild-card male main character with a tendency antagonize adversaries and and not to let others in on his schemes, his UnresolvedSexualTension with his more rational female second, conflicts with authority like the FBI, and so on. Some of the plots, especially in the first season, are similar as well. But as they say in the show, "We're scientists, not magicians," and that's where the shows diverge. Perhaps most notably, the show lets you in on what the LivingLieDetector is seeing and doing, so that the audience member starts to see the cues that they use to see when people are lying. The show quickly comes into its own, and by the second season, it's a real joy to watch Tim Roth play the role of Cal Lightman.[[labelnote:*]]Like it used to be with Simon Baker playing Patrick Jane.[[/labelnote]]

Despite only initially being ordered for 13 episodes, it was a big hit with audiences at first, but its ratings rapidly declined, leading to its cancellation as of May 10, 2011 by {{FOX}}.

For the [[KoreanSeries South Korean series]] of the same name, see ''Series/LieToMeSK''.

----
!!Provides Examples Of:

* AbusiveParents: It's been hinted at that Cal's father wasn't a nice man, but "Funhouse" confirms it:
-->'''Cal''': It takes two to do what? Go down the pub, get drunk every night? You come back rat-arsed, knock your wife and kid about.
** Ria Torres is a more obvious example especially the episode "Delinquent"
* ActionGirl: Detective Wallowski, who's surprisingly willing to kick ass on Cal's behalf, considering he maced her for breaking into his house.
* AmbiguousDisorder: Cal is utterly brilliant. He also has an awkward body language and very little regards to things like tact and the like, and the first line of his second book was, [[spoiler:Let me be clear. I understand very little, least of all the people close to me]].
* AmicablyDivorced: Cal and Zoe.
* AnimalMotifs: Cal's metaphor for women in "Double Blind". He tells Torres to look up the monarch and the viceroy butterflies - predators won't touch either butterfly because they look so similar, but one is harmless and the other is poisonous. He later calls Naomi a "viceroy", because [[spoiler: she's been playing him. Deceptive, and ultimately harmless. It's the monarch that's poisonous.]]
* ArmorPiercingQuestion: The entire team uses them, but Cal's pretty much weaponized them.
* BackStory: Every episode seems to delve deeper into the characters' history, though notable ones are "Depraved Heart", "Secret Santa", and "Sweet Sixteen".
* BadLiar: Virtually everyone who goes up against the Lightman Group.
** Clara. She's fascinated with the work that the Lightman Group does, and it's the impetus for her eventually [[spoiler: becoming a majority shareholder in the company]]. Unfortunately, it backfires on her when [[spoiler: her lack of skill at lying reveals that she'd known about a cover-up involving a gubernatorial campaign and three separate murders]].
* BatmanGambit / GambitRoulette: It's a given that in any episode, Cal will be pulling at least one of these.
** Cal, Gillian, and Burns vs. Little Moon in "Exposure" is one big one: [[spoiler: Cal's mixing lies and his science to prove Burns didn't kill Little Moon's father, Gillian is worried about Burns but backs Cal's play, and Burns is following Cal's lead some of the time and going off script others, and they're trying to keep Little Moon convinced that he needs them all alive]].
** Cal versus Andrew Jenkins in "Blinded": Cal appears to let Jenkins get the best of him at every turn in order to set him for a later fall, and even instigates arguments with his unsuspecting colleagues to entice the necessary reactions from an observing Jenkins.
* BerserkButton: Hurting kids, especially ones that remind him of his daughter, is a very quick to find yourself on Cal Lightman's bad side.
-->'''Cal''': It's more than that, though, isn't it? You hurt a little girl. That's where I come in, because I take that very, very personally.
* BetaCouple: Loker and Torres, to Lightman and Foster's [[EveryoneCanSeeIt alpha couple]].
* BilingualBonus: In the beginning of "Pied Piper", Wilkes is praying the Confietor, the confession of sin from the Roman Catholic church (which is also the origin of the phrase "mea culpa, mea culpa, mea maxima culpa") in the original Latin. The show is also fond of only translating Spanish when it's plot-relevant, so that also probably counts.
* BlackComedy: "What's green and red and goes really fast?" "A frog in a blender." Creepy, but [[SociopathicHero it says something about Cal]] that he knew the punchline before the killer said it.
** About half the dialogue of the Pied Piper, really. What tips it over the edge is the creepy little-kid voice.
* BloodSplatteredWeddingDress: In "Love Always".
* BrandishmentBluff: Torres scares the hell out of a man in the rough part of town by walking aggressively, wearing a hefty jacket, and then shoving her hand into her pocket to grab something. She talks to the man, mentions how he's scared that she has a gun (which is intentional on her part), and then stops the charade and pulls out her card.
* BriefcaseFullOfMoney: What Dr. Lightman purported to be trying to hide when he tested Ria Torres at the airport. After he and Dr. Foster end their hiring pitch, they leave behind the briefcase; when Ria calls them on the "forgotten" item, Lightman says nonchalantly that's her hiring bonus.
* BunnyEarsLawyer: Cal. He sticks his nose into his team's personal business on a regular basis without hesitation, he acts like a JerkAss to ''everyone'' (clients included), and has a fairly big ego. He's also brilliant at what he does. He never seems to miss a single flinch, even on random passerbys.
** The impetus for a scorned girlfriend and her son to come to the Lightman Group in "Rebound".
* CentralTheme: Systematic bias, and how it can affect judgment, cropping up whenever Loker or Torres get involved in a case. Let us say they are both ''passionate''. One episode also implies that bias caused a disaster for Lightman early in his work.
** Another theme that's been popping up is the loyalty between partners (usually a case-of-the-week parallel to Cal and Gillian) and when deception between partners is acceptable.
* ChurchOfHappyology: "Scientific Repatterning" in "Beyond Belief".
* ClearMyName: Reynolds in "Lack of Candor", Cal in "Headlock", Burns in "Exposure".
** Wallowski in "Dirty Loyal" is a [[spoiler: subversion; Cal knows she's guilty and she admits to being corrupt, but they both believe her to not be corrupt enough. Cal convinces Gillian to lie to IA and say that she didn't have direct knowledge of her partner's corruption.]]
* ConfessToALesserCrime: Frequently used by suspects. Justified in that the team can almost always detect if a suspect feels guilty or ashamed, but can't tell why.
* ConsultingAConvictedKiller: Cal pays visit to a serial rapist and torturer for clues about the recent string of copycat crimes.
* CynicalMentor: Helen doesn't quite believe Cal can read people correctly every single time. Of course, she's also [[spoiler: sleeping with Martin Walker and had a relationship with Cal at Oxford]], so her judgment is clouded, to say the least.
* DangerTakesABackSeat: A fugitive takes Torres hostage this way in "Honey".
* DatingWhatDaddyHates: Pretty much any boy Emily Lightman brings home isn't going to be good enough for Cal.
** He's warming up to Liam. Though not enough to stop calling him "Willy".
* DealWithTheDevil: In "Sweet Sixteen", what [[spoiler: Gillian made with Finch and the Pentagon. She would counsel Cal and ensure he didn't expose the cover-up of the Doyle assassination and they wouldn't target Emily Lightman.]]
* DeathByOriginStory: [[spoiler: Cal's mother, who committed suicide after convincing her psychologist she was ready to be released from an institution, and the reason Cal became a psychologist in the first place. If someone had seen her microexpressions, Cal believes, they could have saved her. Any time he deals with a suicide, he's trying to right that wrong.]]
* DelayingAction: [[spoiler: What one CIA agent who'd been abandoned in Afghanistan and went over to the Taliban did to redeem himself.]]
** This was pretty much a HeroicSacrifice for a character we had only seen for that episode. And it was [[CrowningMomentOfAwesome Awesome]]
* MyGodWhatHaveIDone: The killer in "Headlock".
* DisabledSnarker: Sarah, the new grad student in season three, who is also deaf.
* EnhanceButton: [[LampshadeHanging Lampshaded]]. "Can you blow up her eyebrows? And do that thing."
** The show generally doesn't use this - we don't see pixellated pictures get all cleared up... because they're ''already'' all cleared up. It seems all cameras in the show's universe have ludicrously high resolution that lets them keep detail no matter how much one zooms in...
* EmotionsVsStoicism: Lightman and Foster are able to suppress their emotions at all times due to their experience and professionalism, Loker as well for most of the time due to his general laid-back nature (with a few exceptions), but Torres, being the least experienced, has an unfortunate habit of letting her emotions cloud her judgement, and as soon as Lightman sees them having any sort of influence over her, he'll quickly dismiss anything she says (possibly after a bit of mocking).
* ExactWords: In the pilot Lightman's daughter instructs her father not to use any '''covert''' scientific method to find out what they are doing tonight. He agrees so when he meets him he asks point blank.
--> ''Are you planning on having sex with my daughter tonight?''
* FightClubbing: The premise of "Headlock", combined with Cal pulling a "these aren't the droids you're looking for" to ''everyone'' about [[spoiler: the fact that he was at the fight club and was the last person to see the victim alive]].
* FiveManBand
** TheHero - Dr. Cal Lightman
** TheLancer - Dr. Gillian Foster
** TheBigGuy - Ben Reynolds
** TheSmartGuy - Eli Loker
** TheChick - Ria Torres
** TagalongKid - Emily Lightman
* FlashedBadgeHijack: Loker pulls one in "Honey". His "badge" is just his wallet.
* FriendOnTheForce: Detective Wallowski.
* FryingPanOfDoom: Gillian tries whacking one of the attackers in "Delinquent" with her frying pan, but unfortunately, it doesn't do much besides get her tackled by the same guy and tied up.
* GettingCrapPastTheRadar: Half of Zoe and Cal's banter in "The Whole Truth", especially the scene where Cal's locked up and Zoe's deciding whether or not to bail him out.
** In "Killer App", while talking to a geeky web designer (basically Mark Zuckerberg without the movie), we have this delightful little exchange:
---> '''Zach''': "Great. Voice pattern analysis. Which one of you reads palms?"
---> '''Lightman''': "I'll bet yours are sweaty. And hairy."
* GiveGeeksAChance: Cal's ex-wife, Zoe.
* GoAmongMadPeople: Twice. Once in Pied Piper, and again in Funhouse.
* HackTheTrafficLights: A variation in "Saved": the reason a paramedic has a record of saving so many people is because she knows where the traffic accidents will be. Her brother is hacking the traffic lights to ''cause'' those accidents.
* HardWorkHardlyWorks: Dr. Lightman spent years studying microexpressions, while Ria Torres is a natural. In a mild variation, he's actually somewhat bothered by it. However it's also subverted, as Lightman is better at it than Torres and doesn't have emotional blindspots.
** Also subverted in that most of Torres' mistakes come from relying on her natural gift. Lightman does seem to enjoy calling her out on this a bit too much though.
** TruthInTelevision. Paul Ekman, the real life Lightman, found that about 0.25% of the population qualifies as a "truth wizard" (someone able to spot a lie at least 80% of the time).
* HesitationEqualsDishonesty: Deconstructs it: Prepared lies in fact generally cause people to answer quicker, not slower, because they have already prepared their story for questioning. The show goes on to explain that the way to catch these people is to ask them to repeat their story ''backwards'', which is a definite case of ShownTheirWork - your average liar won't bother to practice enough to get this right, but someone telling the truth will obviously be able to draw on their memory to answer (e.g. "I went to the park at about midnight, before that I was at the restaurant, and before that I was out giving candy to orphans.")
* HugeGuyTinyGirl: Loker and his various love interests, including [[spoiler: Emily, in "Bullet Bump"]].
** Emily and new boyfriend Liam.
* HyperAwareness
* IDidWhatIHadToDo: Burns's justification for [[spoiler: shooting Little Moon's father, because his partner was pregnant with the father's baby and couldn't do it herself]].
* IHaveThisFriend: Gillian uses this one when asking Reynolds why [[spoiler: her boyfriend would have a passport in another name and charter a boat out of Baltimore for five hours every week]].
** Turns out he has a very good reason - [[spoiler: he's undercover DEA.]]
* InformedAttribute: Eli Loker is said to be a practitioner of "radical honesty", but apart from an occasional tactless line we don't ever see it, though supposedly it should be quite radical. In fact, a major story arc has him lying extensively and dragging Torres into his lies. He was caught lying about his feelings for a woman, and was insincere about his motives when pretending to be Emily's friend in order to keep an eye on her.
** This may have been true in the beginning, however, one of the plot points of Season 1 was him deciding there were situations where it was okay to lie, and leaving this idea of radical honesty behind him.
* InternalAffairs: IA plays a big part in "Dirty Loyal", where Wallowski and her partner are the target of an investigation.
* IronicNurseryTune: The "Pied Piper" from the same episode sings the "Jack and Jill" rhyme, then [[EvilLaugh giggles high-pitched into the phone]], and says "I'm gonna get you! Ready or not, here I come!" in his phone call to his original victims. 17 years later, he calls the aunt and uncle of his original victims, and sings them "Ring Around the Rosey" with the same ending.
* ItsPersonal:
** Cal and suicides, for very good reason - [[spoiler: his mother was one, and he blames the psychiatrists for not seeing it coming]]. Most notably explored in "Depraved Heart". Also tends to flip his shit if a case involves teenage girls, since it hits close to his own daughter. Abusive fathers also ping Cal's radar, since his father used to get drunk and smack Cal and his mother around.
** Gillian and adopted children - [[spoiler: in "Do No Harm", we find out that she'd once tried to adopt a child, and the girl was reclaimed by her birth mother]] - as well as drug addiction - [[spoiler: her husband Alec is an addict, which is a major factor behind their eventual divorce.]]
** Torres and [[spoiler: domestic abuse - her father used to drink and smack around Ria and her sister Ava]].
* KansasCityShuffle: A fairly brilliant one. In the teaser for "In the Red", Cal inexplicably has joined a bank robbery team. As we learn from the episode-long flashback, Cal actually [[spoiler: saw Miller in the bank, read from his face how badly he wanted to rob the bank, convinced him to hire him on, then immediately went to the bank manager and informed him he was about to be robbed. He convinced the bank manager to cut him in - money which he desperately needs since his accounts are frozen and he's about to be sued by his publishing company for breach of contract - and then turned the bank manager into the police for the inciting error that pushed Miller over the edge.]]
* KeepingSecretsSucks: Torres in the first season because Loker tells her first about his big lie.
* KickTheDog: The goon in "Exposure" who steals a terrified and blindfolded Gillian's money after he's made rape threats to her.
* LastNameBasis: Characters address each other by last name more often than first name.
* LieDetector: Dr. Lightman points out all the ways polygraphs suck. One of them involves getting a guy to fail the control questions by use of a woman in a sexy outfit.
** In "Sweet Sixteen" he used a fake lie detector so the subject would focus on beating that rather than his body language.
** In a season one episode he also taught someone how to "cheat" and make the lie detector read her as truthful, because her story ''was'' true, but the situation made her so anxious that the polygraphs would pick up lies.
* LivingLieDetector: The entire premise of the series.
* LoopholeAbuse: See TwerpSweating below. The daughter specifically asks Dr. Lightman not to do any "covert" lie detection. She neglected to include "overt" lie detection as well. Hence the quoted conversation below.
* LyingToThePerp: Cal, of course. Not just the perps, but material witnesses too.
** One notable example was Cal bringing in the "father" of a girl who had committed suicide to get a guy to confess to "depraved heart murder". It was a mate of his.
** Overt example in "Headlock" where Cal lies to the face of a witness to a fight club [[spoiler: that Cal was not the guy he saw arguing with the victim because it was dark and the witness has "astigmatism"]].
* MaybeMagicMaybeMundane: "Beat The Devil" has the verification of a UFO as its B-plot. Thirty-minute mark, they find (real!) video footage of it. Fifty-minute mark, an Air Force officer shows up with a bullshit story. Loker sees right through him to the truth: The Air Force has ''no idea'' what it was. In the very next sentence, Loker re-established my dormant inner-UFO-nut. '''''The Air Force would NEVER admit to a violation of U.S. air space, not by a Russian MIG or by a UFO.''''' They finally get the witness and the Air Force to agree on a story to save the witness' career - uber-uber-top-secret aircraft. Loker smiles and saves the video to hard drive as the episode ends.
-->'''Loker''': ''The best lies are covered with half-truths. I have no doubt that you had a pilot who cracked, who was shot down everything in that file happened as described. You have no idea what was in the sky that night, do you?''\\
'''Officer''': ''That's the best answer you're going to get out of us, Mr. Loker. If your client's smart, he'll accept it.''\\
'''Loker''': ''Smart? Or spineless. The air force is never going to admit to a violation of U.S. air space, not by a Russian MIG or by a UFO, you and I know that.''
* MayDecemberRomance: A villainous example - Martin Walker and Helen Dezekis.
* MentorShip: Cal and Helen, at Oxford.
* MoodWhiplash: "Tractor Man" ends with [[spoiler: the guy who masterminded the bomb getting sniped through the head.]] The scene that immediately follows is Loker playing the guitar and singing a happy song to a group of children.
* MoralDissonance: Loker. Yay, you made it so thieves got put away. But the people they ruined ''stayed'' ruined. Nice work. * SarcasticClapping* He did get [[WhatTheHellHero called out on it]] beforehand and was punished afterwards.
** In the second season premiere, Cal [[spoiler: threatens to rape a woman, who was raped as a child, in order to speak [[SplitPersonality to one of her split personalities.]]]] He wasn't serious, of course, but saying 'sorry' beforehand does ''not make this okay.'' No other character (including the woman in question, or at least the personality that was threatened) questions what he did afterwards, despite it being ludicrously dangerous, unprofessional, and unethical.
* MostImportantPerson: Cal and Gillian, to each other. Explicitly stated in "The Whole Truth", when Cal says of Gillian (to his RomanticFalseLead, Clara), "she's my Leo" - meaning, she's the person he would trust with everything, including his death.
* MyMasterRightOrWrong: Torres has this for Cal, but in "Pied Piper", Loker calls it into question. Torres accuses him of being a rat fleeing the sinking ship, but Loker (rightly) points out that Cal [[spoiler: got an innocent man executed]]. Unfortunately, Gillian catches them and reams them out, proving her adherance to the trope:
-->'''Loker''': Do you expect us to just share this delusion that Lightman is infallible?
-->'''Gillian''': Without Lightman, you'd be in some university basement doing research, and you [Torres] would still be a glorified baggage handler. Maybe instead of polishing up your resumes, you might want to think about what you can do to help Lightman.
** Averted by Loker, towards both Cal and Gillian. He makes it known from the beginning that he questions their methods, and as time goes on and he [[ButtMonkey constantly takes shit from them]], he believes Cal's outright dangerous and Gillian's a better liar than any of them.
* NoEndorHolocaust: It appears the entire lead cast have an immunity to PTSD. In one episode Cal gets waterboarded. The other surviving victim can barely speak[[note]]Granted she's a long-term depressive, but seriously.[[/note]].
* NoodleIncident: Common. Notably, Lightman has tricked his way past White House security, been banned from Vegas and apparently mooned the Queen. Meanwhile there's Loker's MIT Mathlete initiation, which (suitably) involved macaroni salad.
* NotSoDifferent: In "The Royal We", Cal tells how to create a disturbed personality ("constant criticism and lack of affection"), talking about a pageant contestant. Torres points out, "you mean, [[TheChewToy the way you treat Loker]]". She's right - Cal's jerkass tendencies toward his employees (Loker in particular) have edged into downright cruelty.
** "Funhouse" explores how Cal's mother, Cal, and Emily (who have depression and other mental illness that runs in the family) aren't so different from Wayne's father, Wayne, and Amanda (who have paranoid schizophrenia that runs in the family).
* NotThatKindOfDoctor: Gillian in "Exposed". Cal in "Smoked" and "Saved".
* OutOfOrder: {{FOX}} aired the entire second season in completely random order.
** '''''[[TheFireflyEffect AGAIN.]]'''''
* OverprotectiveDad / PapaWolf: Cal is very protective of his daughter.
* PerpSweating: Along with material witnesses and victims. Cal and Ria's techniques of information gathering waltz into the distinctly unusual.
** Ria:
*** Flirted with a considerable number of men at a frat party to see if any of them are aroused by voyeurism.
*** Took her head covering off inside a mosque to gauge anti-American fundamentalism.
*** Faked hysterical tears to get the head of a juvie facility to allow the Lightman Group jurisdiction on a murder investigation.
** Cal:
*** Showed a suspected statutory rapist pictures of young semi-naked women to see if he's a hebephile.
*** Pretended to have an imaginary friend to determine if a boy can tell reality from fiction.
*** Staged a fight with his daughter on his cell phone in order to see if the parents he was interviewing were abusive.
*** Threatened a girl [[spoiler: with multiple personality disorder]] to get a confession [[spoiler: out of one of her other personalities.]]
*** Fired a gun loaded with blanks inside a locked room in the proximity of the South Korean ambassador.
*** Made out with a murder suspect to gauge the victim's son's[[note]]her step-son; she'd married his dad[[/note]] reaction to her promiscuity (and determine if he slept with her).
*** Cal {{lampshades}} his unusual methods in "Pied Piper": ''"Sometimes you have to use a pickaxe to get at the truth"''. Of course, this is right after he's insulted the aunt and uncle of a murder victim and trashed their bookcase because he thinks they've faked the tape of the killer. They haven't.
*** Allowed a suspected molester, his possible victim, and her mother to be in the same place at the same time, and told the mother the daughter is a sadist. He then invites them to "enjoy the freakshow" and leaves.
** Gillian gets in on the action only a little, notably the time she and Cal staged a fight in front of a woman they suspected of being a victim of domestic abuse. Gillian slaps Cal, but the woman isn't being abused.
*** Also, the time she pulled out the cleavage and short skirt to bait a witness out of a dive bar.
* PlatonicProstitution: The pilot.
* PlotParallel: Often the case of the week has parallels to one or more of the team members and their personal lives.
* ThePowerOfFriendship: The whole point of episode 5 in season 2, subverted through the whole episode until the end.
* RapeAsDrama: In "Blinded", the criminal [[EyeScream blinds]] and then rapes women.
** "Moral Waiver", which is about command rape in an army platoon.
* RapidFireTyping: Oi Loker! Pull up that picture you showed me that other day!
* RetailRiot: The B-plot of the episode "Black Friday" involves the team trying to figure out what caused a fight to break out in front of a store.
* RomanticFalseLead:
** Cal seems to have a thing for hot blondes with whom he's in over his head. First Poppy, the Vegas card shark (or, as Gillian calls her, "roulette"); then Clara, the former gold-digging businesswoman who, as of "Teacher and Pupils" [[spoiler: loans the Lightman Group around seven figures worth of money, making her the lead investor and Cal's new boss]]. She lasts until "Bullet Bump", [[spoiler: when we find out that Clara helped a politician's wife cover up a murder]]. Then there's Naomi, from "Double Blind", who [[DefeatingTheUndefeatable actually successfully cons him]] [[spoiler: except he replaced the diamond with a fake very early on]]. Now it looks like Wallowski's going this way, too, though she isn't a blonde.
** David Burns is Gillian's RomanticFalseLead from "Delinquent" to "Exposure". He seems perfect for her, a gentleman who works with kids and treats her like a princess. Unfortunately, he's [[spoiler: an undercover DEA agent up to his eyeballs in drug trades and gangs, and is, according to Cal, "one of the best liars I've ever seen". After he (along with Cal and Gillian) takes down Little Moon, he walks out on Gillian because the DEA is going to give him a new identity]].
* SassyBlackWoman: Zoe and Emily may be considered as such, given that Zoe is half-black.
* SexWithTheEx: Cal and his ex-wife Zoe can't seem to stop jumping into bed together every chance they get.
* ShoutOut: "Because [[Film/StarTrekIITheWrathOfKhan you always have been, and you always will be...]] my best mate!"
** Cal in the mental institution in "Pied Piper" is one big valentine to ''OneFlewOverTheCuckoosNest'', especially his very [=McMurphy=]-esque canary-eating grin as he gets admitted.
*** "Funhouse", though, takes the expectation of the "Cuckoo's Nest" parallels and then subverts them.
** Cal calls Burns "CaptainAmerica" a few times in "Exposure".
** [[Literature/TheChroniclesOfAmber "What's green and red and goes really fast?" "A frog in a blender."]]
* ShownTheirWork: The show is based off of Paul Ekman's promising, but not-yet-complete, research. It doesn't acknowledge many of the shortcomings in the research (unlike Ekman himself), and doesn't have time to explain the intricacies of the findings, but the principles are quite sound. Anyone familiar with Paul Ekman's research will recognize things in this show, lifted directly from the man's lectures and experiments.
** The pilot, for example, used a clip of a microexpression on Kato Kaelin from the OJ Simpson trial; the exact same clip that Ekman has used in his own lectures.
** Also, pictures of Tim Roth going through the [[http://en.wikipedia.org/wiki/Facial_Action_Coding_System Facial Action Coding System]] are mounted in Lightman's office.
** However, the show leaves fidelity to the real Paul Ekman behind somewhere late in the first season, and only deviates further as episodes wear on.
* SplitPersonality: [[spoiler:Trish/Jessie/Sophie/RJ]]from episode 1 of the second season. Some of the personalities, fitting the fictional portrayal, are aware of one another, though they tend to see one another as different people.
* StalkingIsLove: Cal has been keeping Burns under surveillance, mainly because he's Gillian's boyfriend and Cal doesn't trust anyone around Gillian. Torres is surprised; Loker isn't:
-->'''Loker''': Why? Three guesses - Foster, Foster, and oh yeah, Foster.
* StuffBlowingUp: In "Sweet Sixteen", not only is [[spoiler: the street outside the building where the Lightman Group is located bombed - and Loker caught in the explosion (he's okay, more or less) - but Cal, Gillian, and Doyle are caught in another bomb, rigged at a lawyer's office (they're all okay as well, apart from the lawyer, who's dead)]].
* ThickerThanWater: Do not threaten Emily Lightman. Not only will you have Cal to deal with, but [[spoiler: Gillian as well, before Gillian had even ''met'' Emily.]]
* UsefulNotes/TheTroubles: Cal worked with British intelligence in Belfast in 1986. He failed to recognise the facial expressions of a man who then killed six people in a pub.
** Cal's experience with Irish terrorists is expanded upon in "Sweet Sixteen": In 2003, Cal was in Boston, hunting down IRA members and trying to broker a peace between the IRA and British intelligence. One of the IRA terrorists, [[spoiler: Jimmy Doyle, pinged Cal the wrong way, and Cal believed he would ruin the negotiations. He reported it to the Pentagon, who attempted to assassinate Doyle. Unfortunately, they missed, striking Doyle's wife and daughter, and later covered the murders up. This becomes Doyle's motivation to hunt down everyone involved in the conspiracy, blackmailing Cal to help him.]]
* TooDumbToLive: The conflict of the episode "The Best Policy" is kicked off by a young American man who brings his sister marijuana in a country where possession is an executable offense, and the Lightman Group must assist in negotiating their release. Drug use issues aside, trying to bring narcotics across national borders and through customs checkpoints is risky at the best of times, but one would think that someone even considering it would at least want to ensure that the country they are bringing it into does not have the '''death penalty''' for possession. Flashing the bag of weed on the open road in front of government vehicles does not help either.
* TwerpSweating: Dr. Lightman's daughter gets him to promise not to do any "covert science things", but...
--> '''Dr. Lightman''': Hi, Dan!
--> '''Boy''': Hi, Mr. Lightman!
--> '''Dr. Lightman''': Are you going to try to have sex with my daughter tonight?
** Inverted massively in a CrowningMomentOfFunny during "Killer App." Cal comes home to the sound of Emily making some suggestive noises, only to find her and Liam fully clothed and merely stretching after a jog. Then, with Dad standing right there and her boyfriend stretching her hamstring, Emily proceeds do her [[TheImmodestOrgasm best impression]] of the infamous restaurant scene from WhenHarryMetSally.
* TwoLinesNoWaiting: Usually there are two cases per episode, with Cal and Ria on one, Gillian and Eli on the other. This has been switched up in Season Two with Cal and Gillian on one case and Eli and Ria on the other. One episode of Season Three had Cal and Eli on one case, and Gillian and Ria on the other, with decidedly [[CrowningMomentOfFunny epic]] results.
* TheWarOnTerror: In the first season finale, two American-born suicide bombers attack UsefulNotes/WashingtonDC. [[spoiler: Or so the authorities thought. Turned out they'd been tricked into carrying the bombs.]]
** A second season episode, "Secret Santa", takes place in Afghanistan.
** Turns out Cal isn't the only intelligence expert hanging around. [[spoiler: Gillian, before she and Cal formed the Lightman Group, was a psychiatrist at the Pentagon, counseling operatives of the War on Terror. It's where she first meets Cal, when she was ordered to evaluate whether or not he was still fit for duty after "erratic behavior" and his part in a botched assassination attempt on an Irish terrorist. She's also blackmailed by a high-ranking Pentagon official that if Cal exposes the cover-up, they'll target Emily.]]
** "React to Contact" deals with PTSD and cover-ups among Iraq War soldiers.
* WhatHappenedToTheMouse
** From season one's finale: [[spoiler:Is Ria's partner Kurt still in his coma?]]
** From season two's finale: [[spoiler:Are we going to hear any more on Reynolds, besides a passing comment about him hanging on by a thread?]] Hopefully, this doesn't become a habit.
*** As of "The Canary's Song" we now know that [[spoiler:he's fine, just stuck at a desk.]]
* WhyAmITicking: An episode has Cal investigating on several [[SuicideAttack suicide bombings]] that happened in town. It turns out [[spoiler:they aren't; there is only one terrorist, he's not suicidal and he's been giving camouflaged bombs to innocent people]].
* WhyDidItHaveToBeSnakes: Or, in Reynolds' case - why did it have to be rats?
* WillTheyOrWontThey: Cal and Gillian; expect a couple of seasons' worth of {{UST}}, especially now that [[spoiler: Gillian's single]].
** And that [[spoiler: Cal has admitted to Emily that he loves Gillian]].
** "Fold Equity" suggests that Eli and Ria may experience this as well.
*** "Darkness and Light" guarantees it.
** This series is notable in that it was canceled before this trope could be resolved for anyone. It's highly unusual, and most likely shows how quickly the show fell out of favor with audiences. The spoiler tag above happened on the very last episode, so the writers certainly wanted to return to it.
* WorkingWithTheEx: Cal has to work with ex-wife Zoe on several occasions, and ends up in bed with her a couple of times.
* WouldntHitAGirl: In "Exposure", Little Moon and his gang torture Burns and are willing to rough up Cal, but other than brandishing guns at her and utilizing the StandardFemaleGrabArea, don't touch Gillian.
** Cal subverts it in "Black and White" by macing a female police officer. In his defense, it was late at night, she and her partner had broken into Cal's home, and he blind-fired it around a corner when he heard footsteps.
* XanatosSpeedChess: Cal's manipulation of Terry Marsh, pretending to be blackmailed into working with Marsh and the gangsters he was involved with while really working for the FBI and using Marsh as a pawn the entire time.
** Cal versus Martin Walker in "Beat the Devil", to the point where they even draw comparisons between their conflict and a game of chess.
* YouCanAlwaysTellALiar: The entire '''''point''''' of this series.
** Which, interestingly enough, it subverts in "Dirty Loyal", when [[spoiler: Cal teaches Wallowski to lie, and IA forces Gillian to decide if she's telling the truth. Gillian is torn between her loyalty to Cal, which would mean she'd lie for Cal/Wallowski and say Wallowski isn't corrupt, and her ability to discern truth, which would mean she sent Wallowski to prison because she ''is'' lying. Gillian ultimately lies, causing conflict between her and Cal.]]
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