On behalf of the FBI, the Lightman Group works the case of a copycat serial rapist who blinds his victims. Lightman faces off against the original rapist, a master liar.
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.
Dr. Lightman and Dr. Foster search for the truth in cases involving a devoutly religious high school student accused of killing a teacher, and a congressman accused of having an affair.
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.
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.
The whole Lightman group solves the case of terrorist bombings in the D.C. area. Dr. Foster has escalating problems with her marriage. Torres's boyfriend in the Secret Service is in danger.
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.
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.
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.