Candice Afia

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.

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

Izzie returns to work while the Seattle Grace residents fear possible layoffs; Bailey and Alex's difficult case is further complicated by her schizophrenic son.

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

Cristina and Burke's wedding day arrives - along with the interns' first exam results - and a successor to the Chief is named, as Callie and George make a big decision about their relationship.

Bailey arranges a domino kidney surgery involving all the residents and interns; Meredith is upset Derek didn't include her in the article on their clinical trial.