Eric Dane, Kate Walsh

Another Grey's Anatomy-Private Practice crossover is set for early January. This time, Mark (Eric Dane) and Addison (Kate Walsh) will be featured, TVGuide.com has confirmed.

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According to Entertainment Weekly, the first half of the crossover involves Addison coming to Seattle Grace to perform a surgery on guest-star Leven Rambin (Terminator: Sarah Connor Chronicles). The story concludes with Mark bringing Rambin's character to Los Angeles for more surgery.