Tonight on Grey's Anatomy, we learn more about McDreamy's past than ever before as Addison descends on Seattle Grace - along with Archer, Sam and Naomi - from the alternate world of Private Practice. It's an encore presentation of "Before and After" from this past winter.

If you missed  "Before and After" or just want a full rundown of this terrific ABC crossover action, just follow the link to check out our site's comprehensive episode guide.

Grey's Anatomy videos and pictures from the episode are also live if you need them, as is our music guide and list of great Grey's Anatomy quotes from each week.

As always, until the Season Six premiere on September 24, we will update you on the breaking Grey's Anatomy spoilers, rumors and news as soon as we hear anything!

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