Chuck goes undercover at Sarah’s 10-year High School reunion, where they meet the girl that tortured Sarah back in the old days.

Dismembered remains are discovered in several mailing boxes at a dead letter office, and the Jeffersonian team identifies the victim as an employee of a local Ship ‘n’ Print, where…

The BAU revisits its origins when they look at one of Rossi and Gideon’s old cases to track a killer that got away.