Air Date: January 14, 2010 at 12:00 AM PST
It's time for a Grey's Anatomy-Private Practice
crossover episode! Mark flies Addison to Seattle to help with a difficult procedure on his pregnant daughter, Sloan. Owen questions Teddy's motives when she makes Cristina the lead on a complicated surgery, and Derek becomes suspicious when the Chief recruits Meredith to assist with a high-profile operation.