Meredith和Cristina蜜月归来（买好的机票不好浪费~），Burke已经消失无踪。去年的实习医生Meredith, Cristina, Izzie和Alex，已经获得了正式驻院医生的资格，并且有了自己的跟班，一群初出茅庐，青涩而稚嫩的实习医生。当中，有去年考试不及格的George，还有Meredith素未谋面的妹妹Lexie Grey。今天，他们将要处理一宗三车连环相撞的交通意外，大量的伤者让新来的实习手足无措，目瞪口呆。另一边厢，Derek和Meredith的感情陷入僵局，有可能他们都会和新来的同事有新的感情发展。Bailey对于Callie成为驻院总医生感到气愤，也许她一时三刻还难以接受自己现在要向Callie汇报工作。Richard留任外科主任，仍然是大家的老大~(简介转自YDY)
After failing his exam, George reluctantly faces his first day reliving his internship among a sea of fresh faces. Meanwhile, Cristina, Meredith, Izzie and Alex are in charge of their own interns and George is assigned to Meredith.
Neither Cristina or Meredith have heard from her exes since the wedding, and they don't seem overly concerned, which astounds Izzie, who is counting every day since she last spoke to George. George asks to talk to Meredith but before he can get her alone, the rest of the new interns show up in the hall and are shooed off by the residents. George gives up and joins the interns. Cristina nicknames him "Bambi," saying he needs to learn how to deal with his new situation.