In the first half of a two-part story, no sooner has George's father Harold O'Malley (Geoge Dzundza) nemerged from heart surgery than he must undergo another operation for cancer. Both Meredith (Ellen Pompeo) and Derek (Patrick Dempsey) suffer mightily when Meredith's estranged father Thatcher Grey (Jeff Perry) arrives in town to visit his other daughter Molly and his new granddaughter. While still putting off cashing her huge inheritance check from Denny, Izzie (Katherine Heigl) bonds with Heather, a teenager with a bad attitude, a worse case of spinal curvature, and no money for additional surgery. And the relationship between Cristina (Sandra Oh) and Burke (Isaiah Washington) reaches a whole new plateau. ~ Hal Erickson, Rovi