Derek and Lexie are examining an x-ray of a very complicated tumor. They decide to flip a coin on it. Meanwhile at home, Meredith bakes a cake for Zola's first birthday. Arizona and Callie notice that Mark is second guessing his relationship with Julia, since he found out that Jackson and Lexie have broken up. Chief Hunt shares his concern with Meredith that she is the only fifth year resident without a declared specialty. She discusses with Cristina and Bailey
Bailey and Webber discuss Webber's 10,000th surgery. Derek tells the mother of the patient with a tumor, Wes, that he is going to perform the surgery. The mother informs Derek that Wes doesn't know he has a tumor. Wes tells Lexie that he knows about the tumor and tells her to keep this a secret from his mother. Owen sends Cristina and Teddy home since they've been up for 72 hours. They decide to go against his wishes and they steal Karev's surgery. Karev tells Owen about the surgery and Owen confronts Teddy and Cristina. They do not take him seriously and he walks away while they share a laugh.
In the OR, Webber gets a page that Adele had wandered off. In another OR, Lexie and Derek operate on Wes. It turns out to be worse than expected. Lexie freaks out and Derek orders her out of the OR. Back at home, Meredith throws a birthday party for Zola and invites all the doctors. April asks Karev to move in with her and Jackson and he agrees. Cristina confronts Owen about their argument and he tells her that she is off Teddy's services.