- Ellen Pompeo (Meredith Grey)
- Chandra Wilson (Miranda Bailey)
- James Pickens Jr. (Richard Webber)
- Caterina Scorsone (Amelia Shepherd)
- Camilla Luddington (Jo Wilson)
- Kevin McKidd (Owen Hunt)
- Kim Raver (Teddy Altman)
- Jason George (Ben Warren)
- Chris Carmack (Atticus Lincoln)
- Anthony Hill (Winston Ndugu)
- Adelaide Kane (Jules Millin)
- Alexis Floyd (Simone Griffith)
- Niko Terho (Lucas Adams)
- Harry Shum Jr. (Benson 'Blue' Kwan)
- Trevor Jackson (Wes Bryant)
Grey's Anatomy — S6E4
Episode: Tainted Obligation
Air Date: 2009-10-08
Runtime: 43 min
Overview
When Meredith and Lexie's father, Thatcher, returns to the hospital with a failed liver, it's up to Meredith to save his life. Meanwhile, Izzie empathizes with a patient riddled with tumors, as Mark, annoyed with Cristina's competitive zeal, tricks her into assisting on an unusual surgery.