Meredith takes up knitting and a vow of celibacy. Cristina competes with the Chief during classroom exercises. Burke tries to teach Alex a lesson about bedside manner, but it's a lesson that falls on deaf ears. Izzie knits, too, makes a sweater for Denny, and when she's not knitting, she's trying to get George to move back into the house and at the same time find out from Callie what her secret is (she seems to be hiding something, according to Izzie). George carries around the burden of discovering that Meredith's sister a sister she never knew she had is a patient of Addison's. And Bailey becomes Derek's intern for the day so she can get more OR time. Oh, and Meredith meets Doc's vet.