Grey's Anatomy Season 4, Episode 13 Piece of My Heart Drama IMDB 8.226 Country United States Duration 43 min Air Date 2008-05-01 Actors Ellen Pompeo (Meredith Grey) James Pickens Jr. (Richard Webber) Chandra Wilson (Miranda Bailey) Kevin McKidd (Owen Hunt) Camilla Luddington (Jo Wilson) Kim Raver (Teddy Altman) Chris Carmack (Atticus Lincoln) Jake Borelli (Levi Schmitt) Anthony Hill (Winston Ndugu) Caterina Scorsone (Amelia Shepherd) Overview Addison visits Seattle Grace because they need skills that only she has. Rebecca/Ava returns with news for Alex. Meredith and Derek's clinical trial experiences one or two developments.