Special Guest Stars Patrick Dempsey as Dr. Derek Shepherd Chyler Leigh as Dr. Lexie Grey Guest Stars Griffin Gluck as Mason Warner A.J. Langer as Erica Warner Stephen Amell as Scott Becker Anika Noni Rose as Corinne Bennett Dahlia Salem as Gloria Murphy Jonathan Scarfe as Mr. Murphy Co Starring Scott Alan Smith as Therapist Cory Tucker as Paramedic