The Lightman Group investigates a murder case where a woman with multiple personalities may either be a witness or the killer; and the FBI hires the firm to vet a potential Supreme Court nominee

Zoe enlists the Lightman Group to investigate a star college football player accused of statutory rape; and Foster and Loker travel to a religious compound to find out whether it's actually a nefarious cult.

While on vacation in Mexico, Cal and Emily become involved in the case of a missing American woman; and back home, Gillian investigates tainted blood in DC area hospitals with Cal's rival, Jack Rader.

Eric Matheson, a man suspected of killing his wife, takes over the offices of the Lightman Group, and holds everyone hostage until they find the real killer; Cal's decision to meet his demands and not involve the police may cost him his life.

A face from Cal's past pulls him into a dangerous criminal conspiracy, testing his friendship and loyalty; and the Lightman Group investigates a high school student's homicidal threats.

When a government witness is murdered, the FBI hires the Lightman Group to determine who leaked the witness' whereabouts to the killers, and to protect Agent Reynolds (the star witness in the case); when Reynolds refuses to testify in the case, Cal and Gillian learn he is hiding something in his past.

A troubled teenager believes he was abducted as a baby, and turns to the Lightman Group to help him uncover the secrets of his past; and Eli investigates the origin of a deadly stampede that occurred at a megastore the day after Thanksgiving.

During the holiday season, Cal goes to Afghanistan to assist in a mission to rescue two captured marines, and his only source of intelligence is an American expatriate.

Cal, Gillian, and Reynolds travel to Las Vegas to help locate a missing finalist in the World Series of Poker; Cal uses his skills to read the other competitors' faces to figure out which one knows about the disappearance; and Eli and Torres analyze his new relationship.

Harold Clark, whose farm was recently foreclosed, has set up camp in his tractor outside the White House. An anonymous 9-1-1 call claims he has enough explosives to blow up the entire city. With Cal and the rest of the team on lockdown due to their proximity to the blast zone, it's up to Torres to handle all of the legwork.

Cal plays a dangerous game of cat-and-mouse with a brilliant, charming psychology graduate student; who he identifies as a psychopath; when nobody believes him, Cal sets out to prove the doubters wrong, and catch the psychopath before he kills again; complicating matters is Cal's former mentor, a renowned psychologist who's also been fooled by the charismatic young man, and is protecting him fo.

When an alleged IRA terrorist returns seeking revenge, Cal tries to uncover who was responsible for the murder of the man's wife and child seven years earlier.

Cal agrees to testify for the prosecution until he learns that his ex-wife is representing the innocent defendant: a beautiful younger woman accused of killing her much older, and extremely wealthy, husband.

Cal and the team use cutting-edge science and virtual-reality technology to save the life of an Iraq war veteran and his family. In doing so, Cal confronts unsettling truths about his own past.

While investigating the murder of a police officer, Cal discovers a conspiracy that could threaten his daughter; meanwhile, Cal must get the Lightman Group out from under a financial crisis.

When a pregnant girl is found murdered, Cal and the LMG team help Torres try to clear her juvenile-delinquent sister of charges, and protect her from the real killer.

Cal and Gillian investigate the attempted assassination of the Governor of Virginia; while the Governor came away unscathed, one of his female staffers was killed; Cal quickly deduces that she was the intended target, and assumes someone in the Governor’s campaign (if the not Governor himself) set the entire scenario up to cover-up the murder; Cal and Gillian are tasked with finding the k.

Cal risks being exposed as a gambler in an underground fight club when one of the fighters is found dead. Meanwhile, Gillian's romance with Burns hits a snag when she uncovers a troubling secret.

After watching the first man he helped convict be put to death, Cal thinks he may have been mistaken, and sets out to find the truth; his fears are realized when another boy goes missing under circumstances similar to the original victim.

After Foster's boyfriend, Dave Burns, is abducted, Cal attempts to track him down with the help of Burns' mysterious ex-partner.

The Lightman Group investigates the disappearance of a young woman, which leads them to uncover a criminal element in the adult film business.

The Lightman Group investigates the murder of a journalist friend of Lightman's who was exposing a corrupt politician, a case that tests Cal's relationship with Reynolds and the FBI. Meanwhile, Emily's newfound interest in dating makes her father uncomfortable.