Below are promotional pictures from this week's all-new episode of Grey's Anatomy, "Tainted Obligation." Thatcher Grey is back at Seattle Grace, and he needs a transplant.

Presumably for his liver. Lexie's not a match. That means ... Meredith is likely to devolve into her dark, twisty self as she considers her choice. And we're in for an intense episode. 

Click to enlarge the images below for a little preview of Thursday ...

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