Tainted Obligation

"Tainted Obligation"
Grey's Anatomy episode
Karev screaming after his confrontation with a bear.
Episode no.	Season 6 Episode 4
Directed by	Tom Verica
Written by	Jenna Bans
Featured music	"Trading Things In" "Come On Be Good" "Long Time Gone" "Wish You Well" "Morning Mist"
Original air date	October 8, 2009 (2009-10-08)
Running time	43 minutes
Guest appearance(s)
Jeff Perry as Thatcher Grey Ralph Waite as Irving Weller Jocko Sims as Randy
Episode chronology
← Previous "I Always Feel Like Somebody's Watchin' Me" Next → "Invasion"
Grey's Anatomy (season 6) List of Grey's Anatomy episodes

"Tainted Obligation" is the fourth episode of the sixth season of the American television medical drama Grey's Anatomy, and the show's 106th episode overall. It was written by Jenna Bans and directed by Tom Verica. The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on October 8, 2009. In the episode, Dr. Meredith Grey (Ellen Pompeo) and Dr. Lexie Grey (Chyler Leigh)'s father is admitted into the hospital, seeking a liver transplantation. Further storylines include Dr. Cristina Yang (Sandra Oh) getting nervous about losing her job, and Dr. Owen Hunt (Kevin McKidd) attempting to perform surgery on a terminal patient with Dr. Izzie Stevens (Katherine Heigl).

Although the episode was fictionally set in Seattle, Washington, filming primarily took place in Los Angeles, California. Jeff Perry reprised his role as a guest star, while Ralph Waite and Jocko Sims made their first appearances. The episode's title refers to the song "Tainted Obligation", by American alternative rock group Community Trolls. "Tainted Obligation" opened to generally positive critical reviews, with Pompeo's and Chyler Leigh (Dr. Lexie Grey)'s performances praised in particular. Upon its initial airing, the episode was viewed by 14.13 million Americans, and garnered a 5.4/14 Nielsen rating/share in the 18–49 demographic, ranking third for the night in terms of viewership.