John Thaddeus

The BAU team must profile a serial killer covered in tattoos who commits suicide, but leaves clues to the whereabouts of his last victim. Green Bay Packers wide receiver Greg Jennings guest stars as an evidence tech at a crime scene, and Dean Norris ("Breaking Bad") guest stars as Detective Barton.

The crew of the Serenity are forced to seek help from the Alliance when Book is critically injured in a firefight.

Jack's interrogation techniques are questioned; CTU operatives close in on Marwan; Chloe is forced into field duty.

The CTU apprehends the man who shot Marwan's associate; the president and members of the CTU learn that a nuclear warhead is missing.

A woman's arrest on murder charges leads to a violent showdown in the precinct; detectives question a hostile paraplegic about a deadly rape.

Sipowicz has to make some tough decisions as he starts a new chapter in his life.