Last night on Grey's Anatomy, we learned a bit about Derek's past as Addison, Archer, Sam and Naomi descended on Seattle Grace. But it wasn't all a fun med school reunion.

Everybody battled to treat Archer's devastating condition. They dodged a bullet as McDreamy came through in the clutch - but his other, pregnant patient may not be so lucky.

Elsewhere, Owen was confronted by his ex-fiancee (and Cristina), Alex worried about Izzie's health and pondered his own future after noticing troubling signs, and Sadie left.

If you missed any of "Before and After" or just want a full rundown of last night's 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 live for your enjoyment. Our music guide and list of the best Grey's Anatomy quotes from the night are up too!

Our staff Round Table discussion is still to come, and we'll continue to update you on any breaking Grey's Anatomy spoilers, rumors and news as soon as we hear anything.

As always, our exclusive Grey's Anatomy forum is open for discussion, and comments on all posts are welcome. What did you think of Grey's Anatomy last night? Tell us!

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