George and Derek work together, Denny still doesn't have a heart, and Meredith gets paired with Callie. A 12-week pregnant girl dies in the O.R. and her parents try to keep the baby alive. This causes tension between Derek and Addison. One doctor's overreaction unites two bickering patients. Finn is still treating Doc for medical problems.rnrnPart 1 of a three-hour season finale.