Entering their first year as residents, Meredith Grey, Cristina Yang, Izzie Stevens and Alex Karev now have interns of their own to mentor. The interns are welcomed by new chief resident Callie. Among the new interns are George, forced to repeat his internship after failing his exams, and Lexie Grey, Meredith's half-sister. Many new interns will be introduced in this season premiere. And they'll have their hands full when a three-car accident sends multiple casualties pouring into Seattle Grace. Some of the doctors need to deal with their new stressed out interns. A young boy brings his bleeding deer to the hospital in the hope a doctor will save her. Cristina searches for Burke. Richard resumes his post as chief of surgery. Derek and Meredith reach an impasse. Bailey wrestles with things at the hospital not turning out like she thought they would.