Below is the latest preview of the much-anticipated Grey's Anatomy-Private Practice crossover event, in which the worlds of Shonda Rhimes collide on Thursday night.

Here's what happens in L.A. between Private Practice's Addison and her brother, Archer, that prompts her to seek help from Derek, her famous Grey's Anatomy ex ...

[video url="http://www.greysanatomyinsider.com/videos/greys-anatomy-private-practice-crossover-sneak-preview/" title="Grey's Anatomy-Private Practice Crossover Sneak Preview"] [/video]

For another sneak preview - this time from the Seattle Grace side of things - follow the jump. Then follow this link for the latest Private Practice and Grey's Anatomy spoilers!

[video url="http://www.greysanatomyinsider.com/videos/beat-your-heart-out-sneak-preview-1/" title="Beat Your Heart Out Sneak Preview #1"] [/video]

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.