Taking a step farther than their mother did and learning the nature of the object at the heart of the mystery, Frank and Joe's unity fractures over what to do next. Tensions between Chet, Callie, Frank and Stacy reach a peak.

The Runaways become suspicious of one another with a traitor among them. Catherine takes responsibility for her past. Leslie seeks help protecting the child growing inside her.

When Monk's neighbor Kevin is found dead backstage at a magic show, Monk begins to suspect Kevin's old mentor, The Great Torini. The problem is, he has a perfect alibi.

Saul finds Carrie hospitalized and manic, but realizes her chaotic theories have merit; before his congressional campaign begins, Brody takes his family on a weekend trip to Gettysburg.

Reese must protect an investigative journalist without her knowing it or risk becoming part of her story.

The team searches for more clues after the Uzi from the shootings is found in the church, but the bad blood between Hickman and Tao reaches the boiling point. Meanwhile, more clues indicate that Rusty's mom may be in danger.

When Atwater goes undercover in a drug syndicate, he learns there may be more to its kingpin than meets the eye; Halstead tries to join Atwater undercover, but finds himself at a disadvantage.

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.

Taking a step farther than their mother did and learning the nature of the object at the heart of the mystery, Frank and Joe's unity fractures over what to do next. Tensions between Chet, Callie, Frank and Stacy reach a peak.

Reese must protect an investigative journalist without her knowing it or risk becoming part of her story.

When Monk's neighbor Kevin is found dead backstage at a magic show, Monk begins to suspect Kevin's old mentor, The Great Torini. The problem is, he has a perfect alibi.

When Atwater goes undercover in a drug syndicate, he learns there may be more to its kingpin than meets the eye; Halstead tries to join Atwater undercover, but finds himself at a disadvantage.

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.

Saul finds Carrie hospitalized and manic, but realizes her chaotic theories have merit; before his congressional campaign begins, Brody takes his family on a weekend trip to Gettysburg.

The kids search for Leslie and Alien Alex. Meanwhile, Leslie gives birth and Xavin fulfills her prophecy. The kids go head to head in a final battle against the aliens.

Trapped and lost, Biff and Joe's friendship is tested. Frank can only help find them by revealing too much to people he can't trust.

Desperate to save the parking lot where Trudy was killed from demolition, Monk enlists the help of a sympathetic councilwoman. But when she goes missing, Monk may be forced to deal with her hapless and incapable assistant.

A major figure in the case is dead from a suspected overdose, but Tao thinks he was murdered. A major revelation casts Mark Hickman's motives in doubt, and a new suspect emerges on the day of the memorial service for the original victims.

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.

Reese is out of his element when The Machine's latest number sends him to the suburbs, forcing him to play house and go undercover in an idyllic neighborhood.

While Carrie is near catatonic, Saul investigates her unsettling timeline; Brody makes final preparations for the Vice President's policy summit at the State Department.

After a botched carjacking turns out to be something much bigger, Voight's unit goes toe-to-toe with a smart drug kingpin who only works with women. New recruit Vanessa Rojas struggles with the transition from undercover to Intelligence.

On Allie's birthday, Tory, Matthew and Jasper try to find the best way to confront their grief and honor her memory; Elena discovers someone she trusts is lying to her.

A major figure in the case is dead from a suspected overdose, but Tao thinks he was murdered. A major revelation casts Mark Hickman's motives in doubt, and a new suspect emerges on the day of the memorial service for the original victims.

Reese is out of his element when The Machine's latest number sends him to the suburbs, forcing him to play house and go undercover in an idyllic neighborhood.

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.

While Carrie is near catatonic, Saul investigates her unsettling timeline; Brody makes final preparations for the Vice President's policy summit at the State Department.