After learning at a deposition that more of his patients have died than survived, Derek decides to quit, but Meredith refuses to give up on him.
Derek's mother makes a surprise visit to Seattle and meets Meredith for the first time. Meanwhile, Owen and Cristina try to go on their first date.
Derek's confidence is shaken as he faces off with Addison over the best course of action for their dying pregnant patient.
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.
Now that Derek has the engagement ring, he searches for the perfect way to propose to Meredith.
Everyone in the hospital is stepping up to try to find the boy a new organ donor.
Cristina and Meredith try to put their differences aside to treat a prisoner on death row with a serious brain injury; Bailey is put on her heels by a new pediatric surgeon.
Bailey teams with Seattle Grace's new pediatric surgeon, Dr. Arizona Robbins, to save the life of a young patient near and dear to her heart.
Cristina is awarded the first solo surgery among the residents, but she has to relinquish it and choose her replacement.
Meredith's old friend Sadie becomes an intern at Seattle Grace, but Meredith's other friends aren't exactly welcoming.
With solo surgeries for the residents pending, the interns and residents scramble for practice and a way to prove themselves.
Major Owen Hunt returns to be the head of ER trauma; Meredith finds an old doll her mother gave her when she was 5.
Bailey heads up a "domino procedure," in which each surgery hinges on the one preceding it.
Tension arises between Derek and Meredith's mother; Cristina is mesmerized by the lifestyle of working in the dermatology wing.
A plumbing leak becomes a flood and wreaks havoc at Seattle Grace. The chief attempts to implement new teaching policies.
Meredith and Derek rediscover the morning-after side of their relationship; the chief learns the hospital has slipped in the national rankings.
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