10:43am PT by Lesley Goldberg
'Grey's Anatomy': Kate Walsh, Kate Burton Returning for February Episode
Grey's Anatomywill welcome a few familiar faces for a special February sweep episode in which Derek (Patrick Dempsey) and Addison (Kate Walsh) never broke up.
Titled "If/Then," Walsh broke the news via Twitter that she'd be returning for the special alternate reality-themed episode that will also feature the return of Meredith's (Ellen Pompeo) mother, Ellis Grey, The Hollywood Reporter has confirmed.
As first reported by EW, Burton will appear in the episode and explore how Meredith's life would be different if her mother, who died during Season 3, were still alive -- as well as what that would mean for Ellis' affair with Chief Weber (James Pickens Jr.).
Meanwhile, Grey's insiders say there will be additional guest stars for the February episode, which also will include a victim from the hospital shooting in the Season 6 finale. Who do you think will return?
Burton, meanwhile, will next be seen in a multiepisode arc on Grey's creator Shonda Rhimes' upcoming ABC political fixer drama Scandal, as the vice president.
Grey's and Walsh-starrer Private Practice return in January.