Eric Ramey

The BAU travels to Los Angeles to investigate unusual murders throughout the city. Also, more of Prentiss' mysterious past comes to light.

Meredith finally tells Derek about her pregnancy and miscarriage; during a surgery, Cristina experiences PTSD; Bailey won't let Alex operate until he has the bullet in his chest removed.

The BAU searches Los Angeles after the team discovers security footage that shows an UnSub being invited into victims' homes.

A professor from Lewis' past tips off the BAU to an alarming number of overdose deaths of patients who just completed rehab.

After an ambush changes the course of the their investigation, the NCIS team has to quickly find answers, and one team member flashes back to their very first NCIS assignment.