Loretta Devine Returns as Adele Webber Edward Herrmann ("Gilmore Girls") Guest Stars as Doctor Norman Shales "The Heart of the Matter" - The Chief's wife, Adele, rushes their niece to Seattle Grace, the hospital where she once had her prom, Izzie reveals her feelings for George to a mutual friend, and the reaction is not what she expects, Derek teaches Cristina how to be a better teaching resident, and the world's oldest living intern, Norman, misdiagnoses one of Meredith's patients, on "Grey's Anatomy," THURSDAY, DECEMBER 27 (9:00-10:02 p.m., ET) on the ABC Television Network. (Rebroadcast. OAD 10/18/07)

"Grey's Anatomy" stars Ellen Pompeo as Meredith Grey, Patrick Dempsey as Derek Shepherd, Sandra Oh as Cristina Yang, Katherine Heigl as Isobel "Izzie" Stevens, Justin Chambers as Alex Karev, T.R. Knight as George O'Malley, Chandra Wilson as Miranda Bailey, James Pickens, Jr. as Richard Webber, Sara Ramirez as Callie Torres, Eric Dane as Mark Sloan, and Chyler Leigh as Lexie Grey.

Guest Cast: Edward Herrmann as Norman, Michael McGrady as Stanley, Matt Lanter as Adam, Maggie Siff as Ruthie, Miriam Flynn as Ms. Bitzer, Camille Winbush as Camille, Ron Melendez as Will, with Loretta Devine as Adele.

"The Heart of the Matter" was written by Allan Heinberg and directed by Randy Zisk.

"Grey's Anatomy" is broadcast in 720 Progressive (720P), ABC's selected HDTV format, with 5.1-channel surround sound and Spanish audio via SAP. This program carries a TV-14,L parental guideline.

This episode of "Grey's Anatomy" will be available on ABC.com the day after airing on the network for users to watch online.