The FBI asks The Lightman Group for help after a terrorist bombing outside Washington, D.C.. Meanwhile, Zoe and Cal are both looking after their daughter's safety.

The Lightman Group partners with an FBI agent to go after a serial rapist who's been terrorizing Washington D.C..

The group investigates a controversial case about a cop who shot an innocent teenager. Meanwhile, The Lightman Group is sued.

The Lightman Group is hired by Cal´s ex-wife to help with an arson case.

Dr. Cal Lightman and his colleagues investigate a construction site building collapse. They attempt to save three men trapped inside the building.

The team tries to help a group of investors who were scammed for millions of dollars. Meanwhile, Lightman investigates the case of two women who committed suicide.

Cal is hired to find a spy at a pharmaceutical company, but instead discovers a conspiracy regarding a new drug that can put many civilians at risk. Meanwhile, The Lightman Group assists with negotiations for the liberation of two Americans being held captive in Yemen.

Gillian and Cal investigate the disappearance of an 11-year-old girl who is believed to have been murdered. Meanwhile, Eli and Ria must determine whether a renowned peace activist is really who she claims to be and if her novel is factual. However, Eli's attraction to the woman gets in the way of his ability to clearly do his job.

Ria and Cal question a former gang leader who claims to be rehabilitated. Meanwhile, Eli and Gillian look into the death of a firefighter who was killed in the line of duty.

The team tries to prevent the assassination of a South Korean ambassador at a state wedding, but the case takes a different turn when someone else is shot instead.

When the daughter of a federal judge is murdered, The Lightman Group holds an investigation at the girl's ultra competitive high school. Meanwhile, the team also investigates the case of a NASA test pilot when the subject is accused of intentionally crashing a multimillion dollar aircraft.

Cal and Ria investigate the case of a female soldier who claims to be the victim of sexual assault by her commanding officer. At the same time, Gillian and Eli work on the case of a college basketball player who is accused of accepting a bribe from his university.

The murder of a teacher prompts The Lightman Group to investigate a student who was seen fleeing the murder scene. Meanwhile, the team also takes on the case of a politician who is accused of paying for sex.