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.
Cal joins a bank robbery crew in order to sabotage the heist from the inside, but he soon discovers that one of the men on the job has a very personal motive.
While Cal suffers writer's block and the office suffers from personnel issues, the Lightman Group investigates charges of abuse and molestation at a teen beauty pageant.
The Lightman Group is hired to examine police profiling techniques in the wake of an incident involving Wallowski, and Internal Affairs attempts to leverage Lightman's relationship with Wallowski to get him to incriminate her.
While vetting an art museum staff for security leaks prior to a major exhibition, Lightman meets a beautiful woman who entangles him in a game of cat-and-mouse.
While Dr. Lightman investigates who was responsible for a deadly coal mine explosion, the FBI questions Dr. Foster about Dr. Lightman's gambling associates.
Dr. Lightman goes all-out to expose a self-help cult leader after one of its members tries to commit suicide but quickly returns to the fold despite the protestations of her daughter.
Dr. Lightman helps a woman with early-onset Alzheimer's Disease uncover a traumatic memory from her past, and in the process discovers that there may be an "Angel of Death" working in her health care facility.