Grey's Anatomy Season 5 Episode 7

Meredith's best friend from college shows up on her doorstep and Cristina feels threatened by it. Meredith thinks Sloan is putting the moves on her half-sister and asks Derek to intervene, while the interns practice sutures on each other and Izzie still feels Denny's presence. Hahn is suddenly gone from Seattle Grace and everyone immediately feel at odds over her replacement.