Twelve years ago, Jack worked a serial killer case in which five women were murdered. Now, Jack and the team search for a missing woman whose description is remarkably similar to the five murder victims from long ago.

Jack and his team search for a teenage boy, Ethan Sawyer, after he disappears from his home.

Ben heads down a slippery slope as he attempts to help the daughter of a prostitute. Tang faces more questions about shooting an innocent bystander -- which could affect her future.

The holiday season screeches to a halt when six members of the Anderson family are discovered to have been gunned down in their home. Detectives work closely with family friends to track down the shocking murderer.

After a break-in turns into a homicide, Murtaugh and Riggs set out to find the culprit. Murtaugh and Trish question their trust in Riana as she gets into trouble with friends. Meanwhile, Riggs recalls his troubling childhood and finds a true family with Molly and Ben.

On Murtaugh's first day on the job as interim captain, the wife of a popular businessman is abducted and the squad finds a connection in the case to Rigg's father. Meanwhile, Riggs is left to grapple with his family and work.

When a member of Cho's former gang, the Avon Park Playboys, is found murdered, Patrick Jane insists on helping Cho with his off-the-books investigation.

Ben heads down a slippery slope as he attempts to help the daughter of a prostitute. Tang faces more questions about shooting an innocent bystander -- which could affect her future.

Herrmann and Mouch prepare to take their officer exams. Cruz receives a chilling omen. Carver takes care of a dog after its owner is injured on a call.

The holiday season screeches to a halt when six members of the Anderson family are discovered to have been gunned down in their home. Detectives work closely with family friends to track down the shocking murderer.

On Murtaugh's first day on the job as interim captain, the wife of a popular businessman is abducted and the squad finds a connection in the case to Rigg's father. Meanwhile, Riggs is left to grapple with his family and work.

When a member of Cho's former gang, the Avon Park Playboys, is found murdered, Patrick Jane insists on helping Cho with his off-the-books investigation.

Ben heads down a slippery slope as he attempts to help the daughter of a prostitute. Tang faces more questions about shooting an innocent bystander -- which could affect her future.

Jack and the team search for a brilliant but complicated 14-year-old Russian violinist, Natasha Tzetcovich, who disappeared after a rehearsal for an important concert appearance.

Twelve years ago, Jack worked a serial killer case in which five women were murdered. Now, Jack and the team search for a missing woman whose description is remarkably similar to the five murder victims from long ago.

Jack and his team search for a teenage boy, Ethan Sawyer, after he disappears from his home.

The holiday season screeches to a halt when six members of the Anderson family are discovered to have been gunned down in their home. Detectives work closely with family friends to track down the shocking murderer.

Herrmann and Mouch prepare to take their officer exams. Cruz receives a chilling omen. Carver takes care of a dog after its owner is injured on a call.

On Murtaugh's first day on the job as interim captain, the wife of a popular businessman is abducted and the squad finds a connection in the case to Rigg's father. Meanwhile, Riggs is left to grapple with his family and work.

When a member of Cho's former gang, the Avon Park Playboys, is found murdered, Patrick Jane insists on helping Cho with his off-the-books investigation.

Ben heads down a slippery slope as he attempts to help the daughter of a prostitute. Tang faces more questions about shooting an innocent bystander -- which could affect her future.

Pope applies for the police chief job.

Torres is haunted by his previous transgressions as Cook takes on a tense undercover assignment.

The Unit learns the truth about a secret Torres has been keeping as Deputy Chief Charlie Reid puts a focus on Intelligence.

A local woman with second sight triggers chilling memories that point to Emma's involvement in Theresa's death and lead to a disturbing discovery of further damage to girls at the group home. John draws closer to Emma and Mary clears her life of everything but revenge.

Emma finds herself isolated and finally making sense of a past with Kit. To assuage her guilt she pursues the truth about Jess and puts herself in further danger. Mary numbs her pain with sex and drugs and renews John's task, unaware he is reaching his dangerous peak.

Jane and the team investigate the murder of an arrogant chef during a cooking competition in Napa Valley.

The Unit learns the truth about a secret Torres has been keeping as Deputy Chief Charlie Reid puts a focus on Intelligence.