Kate Walsh: Grey's Anatomy and Private Practice Crossover!

Kate Walsh holds onto her mother Angela‘s hand as they leave a senior citizen’s center in Los Angeles on Sunday afternoon (November 8).

SPOILERS: Private Practice‘s Addison (Walsh) is heading back to Grey’s Anatomy in early January. Mark (Eric Dane) needs Addison to perform surgery on a woman from his past, Riley Dawson (Leven Rambin). The rumor is that she’s Mark’s daughter. Riley first makes her appearance on Grey’s on Nov. 19.