The staff tries to deal with physical and emotional trauma in the wake of the vengeful gunman's deadly rampage; Derek makes a spontaneous decision to resign as chief and return to surgery.
Amelia arrives at Seattle Grace to beg Derek to help with the gliosarcoma case; Cristina and Owen have heated arguments during marriage counseling; Alex realizes he needs to improve his people skills in order to be a good doctor.
Mike Delfino remembers scenes from his past; problems at Scavo's Pizzeria cause conflict in Lynette and Tom's relationship; Orson reveals his hidden past to Bree.
Rex Van De Kamp narrates the happenings on Wisteria Lane; Edie gets an unexpected visitor from her past; an unanticipated pregnancy creates complications.
Bree's forced to handle catering for Bob and Lee's wedding by herself when Katherine bails out; Gaby gets a call from Ellie; Julie finds out about her acceptance to Princeton, but Susan doesn't want her to go.