Izzie realizes that she is attracted to her patient with a heart condition. George treats Bex, a hermaphrodite. Meredith's mother gets a special visitors. Derek and Addison's relationship is still rocky.
Cast: Ellen Pompeo, Sandra Oh, Katherine Heigl, Justin Chambers, T.R. Knight, Chandra Wilson, James Pickens Jr., Kate Walsh, Isaiah Washington, Patrick Dempsey, Stephen Spinella, Jeffrey Dean Morgan, Lauren Tom, John Prosky, Becca Gardner