"Grey's Anatomy" is going "Fringe" in an upcoming episode. It has been reported that the medical drama show will take the Seattle Grace doctors to an alternate reality in a February 2012 outing as the episode launches a question, "What if things had been different - very different?"
The question apparently represents what's in Meredith's head as she imagines what life would've been like had her late mother Ellis never had Alzheimer's. One thing that would probably happen is that Derek and Addison never broke up.
While a representative for the Shonda Rhimes-created series declined to comment, an insider has confirmed to TVLine that Kate Walsh will indeed return as Addison in the episode. Although she will be the only series regular returning to the show, more "Grey's Anatomy" alums will make appearance as well, including an unnamed victim of the Seattle Grace Massacre in 2010.
The eighth season of "Grey's Anatomy" will return with new episodes starting January 8 at 9 P.M. on ABC.