Amrapali Ambegaokar

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 residents and interns treat the victims of a massive explosion at an apartment building, while Alex investigates the cause of the accident.

Tension arises between Derek and Meredith's mother; Cristina is mesmerized by the lifestyle of working in the dermatology wing.

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.

Cristina and Meredith try to put their differences aside to treat a prisoner on death row with a serious brain injury; Bailey is put on her heels by a new pediatric surgeon.

George and Izzie's romantic chemistry is put to the test. Mark develops a crush on a fellow surgeon. Callie's role as chief resident is in jeopardy.