Melvin Abston

A young woman wakes up in the hospital with no memory of her assault, and Carisi's (Peter Scanavino) investigation stalls when she disappears.

When a teenage sex worker disappears, Rollins and Velasco find a key clue in a pile of neglected missing persons reports.

The hospital is hit with an unprecedented crisis; Meredith and Cristina's surgical skills are put to the test.

After a former officer waits on Frank at a restaurant, he feels guilty about the circumstances surrounding why she was fired, and he tries to reinstate her. Also, Danny and Baez investigate the murder of a star college basketball player linked to sports betting, Erin seeks justice in an apparent DUI, and Jamie and Eddie pick a wedding venue.

A gunman open fires at a local college, sending mass casualties to the hospital; Arizona's return is not warmly welcomed.

When Sabrina is arrested after attending an Occupy Natesville protest, one of the jail attendants (Katy Perry) commits to making her imprisonment as awful as possible; Virginia helps the mayor avoid a scandal.