Amrapali Ambegaokar

Meredith and Derek rediscover the morning-after side of their relationship; the chief learns the hospital has slipped in the national rankings.

Derek prepares to perform his first surgery since his breakdown; Owen has a PTSD episode which injures Cristina and puts their relationship in jeopardy.

The hospital has a pipe break which causes a huge flood; Meredith quits therapy but Dr. Wyatt doesn't believe she is finished.

Meredith, Cristina, Izzie and Alex spend their first day as residents with their own interns, including George, repeating his internship after failing his exams, and Meredith's half-sister. Cristina searches for Burke, who is nowhere to be found and Richard resumes his position as chief of surgery.

Meredith and Derek rediscover the morning-after side of their relationship; the chief learns the hospital has slipped in the national rankings.

Major Owen Hunt returns to be the head of ER trauma; Meredith finds an old doll her mother gave her when she was 5.