Molly Kidder

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

The ER is filled with teenagers after a schoolbus crash, Bailey treats a patient who was her high school crush, Derek goes out on a date with a fellow doctor.

Derek searches for the best way to propose to Meredith; Callie tries to convince Mark not to blow his chance at real love with Lexie, despite his fear of Derek finding out; Izzie learns she has anemia.

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.

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

Addison, Naomi and Sam rush Archer to Seattle Grace to try and save his life; Owen runs into a significant someone from his past; Izzie employs her fellow doctors in a medical game to teach the interns.