A face from Derek and Addison's past arrives in Seattle to shake things up; Burke learns Cristina's secret; Meredith looks into her family's secret history.
Michael's behaviour grows increasingly careless as his new boss is more watchful; Pam has issues with a difficult copier; Kelly develops a new crush.
The BAU profiles an entire community when three college athletes disappear on the night of a pep rally, and JJ is crucial in moving the case forward.
Jax has to decide whether to kill Clay and take over the presidency of Samcro. Two members of the Galindos reveal themselves to have mixed loyalties, and Tara has her own decision to make about whether to stay or go.
Survivors of the Communist witch hunts of the 1950s see their pasts catch up with them. Rush looks into the case of a schoolteacher who was murdered in 1953 and suspects a possible connection with the anti-communist fervour of the times.