— Drink it in: At Thanksgiving, the Chief told Meredith that he doesn't consider himself an alcoholic, she agreed not to tell anyone she'd seen him drinking, and they began to bond. At Christmas, though, when Meredith saw her father, Thatcher told her there was no way the Chief could take back his alcoholism. By New Year's, though the Chief had told Meredith he was giving up drinking again, she was later called to the bar to collect him, because he was spectacularly drunk.
The holiday in your heart: Teddy and Cristina's patient had a malfunctioning heart that had to be removed, so they placed her on machines. Her date who brought her in decided to stay with her at the hospital. At Christmas, she was still there, desperate to see snow before she died — and her date was still there, too. Teddy managed to get her outside for the snow, but by New Year's, she was desperate for a donor heart. In the end, she got a new heart, her faithful date proposed, and she accepted.
Old flame wars: Teddy and Owen kept trading longing looks, and he eventually confronted her over it. He confessed that he had feelings for her when they knew each other, just as she confessed last week. "I have loved you forever," she said. Though tempted, he told her he was in love with Cristina. Later, Cristina tried to let Owen out of their relationship if he wanted, but he vowed that he loved her.
Mean dad: Bailey hadn't told her parents about her divorce as of Thanksgiving, but when her father showed up for Christmas, he'd already heard. Even after seeing her do surgery, Bailey's father excoriated her for giving up her family for her career, calling her both a bad mother and a bad wife. Desperate for support, Bailey landed an invitation to Meredith and Derek's giant Christmas dinner, where she and her father made a scene by loudly arguing about her choices. Fortunately, they at least partially reconciled in time for New Year's.
The right tools are everything: Derek began brain surgery on a young boy, but discovered he couldn't repair the problem without special instruments made to order. When the project couldn't be funded by Christmas, Derek banded together with Arizona and Mark to pay for it. The surgery finally happened on New Year's Eve, and the boy recovered.
Hi, Dad! And Grandpa!: Mark Sloan got a shock when a young woman showed up and said she was his daughter — and paternity testing backed her up. Lexie, naturally, was a little weirded out by the idea of her boyfriend having a daughter not much younger than she is. The daughter (whose name is Sloan, confusingly enough) then moved in with Mark and Lexie. When she was still there on New Year's Eve, Lexie insisted that Mark inquire about her plans. When he did, he learned that she was pregnant and had nowhere else to go.