The service offered by The Lightman Group is truly unique. Simply stated, they can tell if you're lying. It's not the words you speak that give you away, it's what your body and face have to say. Dr. Cal Lightman and his team are experts at reading micro-expressions, the fleeting tics that express, non-verbally, what we are really feeling. With their finely honed interviewing and investigating skills, they have an uncanny ability to dig up the truth.
Cal tries to thwart a bank robbery from the inside by forcing his way into the gang, and tries to talk one of the robbers out of seeking revenge for the bank erroneously foreclosing on his home.
Cal dives head first into the world of beauty pageant teens and their obsessive parents who won't stop pushing them. He strives to mend a broken relationship between a dysfunctional mother and daughter while at the same time, prove a man has been unjustly accused of assault.
Cal has a personal interest in an Internal Affairs investigation of a police officer, accused of murdering a gang banger.
Ria blames herself when two museum security guards, that she vetted and approved, try to steal a valuable artifact. Both men are shot and killed by another guard, who is devastated that he killed the two men. Meanwhile, Cal becomes involved in a game of cat-and-mouse with a beautiful woman and the man who is stalking her.
Cal puts his life on the line when he goes below to investigate an explosion that killed six coal miners. Gillian does a final favor for the FBI in exchange for getting both Cal and the Lightman Group out from under their thumb, once and for all.
Cal goes head-to-head with a cult-like self-help guru, as he tries to free a wealthy woman from his control. As the investigation progresses, Cal starts playing hard-ball when veiled threats are made towards Emily.
Cal goes out of his way to help a woman with early-onset Alzheimer's, who claims a man named Charlie killed her sister, Rose, and now he's after her.
Cal assists Det. Wallowski investigate the murder of the daughter of a terminally ill friend of hers. Meanwhile, Ria is mugged in a rough neighborhood and goes looking for the guy who did it.
Emily seeks Cal's help for her friend who is worried about her dad, who has been in a psychiatric facility for 5 years. Cal is immediately suspicious of the facility and puts his own sanity on the line when he gets himself committed so that he can work the case from the inside.
A wealthy woman asks Cal to check out her new boyfriend when her son discovers a briefcase filled with cash and a notebook in code.
Cal investigates a deadly traffic accident caused by three high school students on a joy ride, and stumbles onto something much bigger.
After a baby goes missing, the investigation zigzags all over the place until Cal and his team open a massive can of worms, revealing a family completely crippled by their dysfunction.
Series finale Cal takes a wicked pleasure in wiping the arrogant smirk off the face of a computer entrepreneur who Cal believes murdered one of his partners and framed his other partner in order to gain full ownership of a successful social networking site the three created together.