Dr. Lightman tries to figure out whether a woman with multiple personalities witnessed a murder, while Torres interrogates a judge who is being considered for a Supreme Court appointment.
Zoe gets Dr. Lightman's help in a case involving an African-American college athlete accused of statutory rape, and Dr. Foster tries to help a sympathetic mother while investigating a religious leader for the IRS.
While on vacation in Mexico, Lightman and Emily become involved in the case of a missing American woman. Back home, Foster investigates tainted blood in D.C.-area hospitals with Lightman's rival, Jack Rader.
An old friend from Lightman's past comes for help, and gets Lightman involved with a dangerous man being investigated by the FBI. Meanwhile, the rest of the team tries to find the high schooler behind a dangerous and threatening video.
Agent Reynolds refuses to testify in an undercover case from his past because it may reveal that he killed a man during the operation, but Dr. Lightman tries to come to his defense and keep him out of harm's way.
Dr. Lightman and Dr. Foster help an angry teen find his birth parents, while Eli and Ria try to figure out who was responsible for a fatal "Black Friday" trampling incident at an electronics store.
During the holiday season, Lightman goes to Afghanistan to assist in a mission to rescue two captured marines, and his only source of intelligence is an American expatriate.
Dr. Lightman, Dr. Foster, and Agent Reynolds go to Las Vegas to investigate the disappearance of an unlikely finalist in a poker championship, and none of his fellow finalists are above suspicion.
A frustrated farmer with a bomb drives his tractor to Washington and demands to talk to the president, and Cal is brought in to find out who's really calling the shots.
Dr. Lightman is convinced that one of his former protégé's students is a sociopath connected to a woman's disappearance, but everyone else is skeptical. Meanwhile, Torres and Loker help a high school teacher who thinks he saw an UFO.
An Irish terrorist comes to Dr. Lightman to find out who killed his wife and daughter seven years ago, which reveals secrets about Lightman's relationship with Dr. Foster and his past job working counter-terrorism for the government.
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.
A decorated war hero who is suffering from Post-Traumatic Stress Disorder claims that someone is trying to kill him, and Dr. Lightman is brought in to investigate.
Dr. Lightman allows a wealthy client to shadow him as he tries to find out who critically wounded a Washington, D.C. police officer in an apartment building taken over by drug dealers.
Dr. Lightman helps Torres's half-sister, who is serving time in a juvenile facility, after an fellow inmate who asks for her help is killed. However, Torres is not convinced that her sister can be trusted.
The Lightman Group discovers that a governor's staffer who was killed during a rally right before the election may have been the target all along to protect a cover-up, and Clara might be lying to protect somebody on the inside.
The FBI investigates the murder of an illegal underground fighter, but Dr. Lightman tries to conceal his relationship to the event. Meanwhile Dr. Foster discovers that her new boyfriend may have a big secret.
The future of The Lightman Group could be in jeopardy when it appears that an executed prisoner that Dr. Lightman helped convict may have been innocent of the crime.
After Dr. Foster's boyfriend is kidnapped, Dr. Lightman discovers that he is an undercover DEA agent who may have killed the father of his kidnapper in the line of duty.
The Lightman Group helps a father find his daughter, who left home and became a porn actress, but Cal soon suspects that he's keeping something from him. Meanwhile, Eli and Ria compete for a promotion.
Dr. Lightman's journalist friend is murdered while investigating political corruption, and agent Reynolds is critically shot during the ensuing investigation.