Breaking up is hard to do, but sometimes it can be downright dangerous. Matt Saunders (Luke Wilson) thinks he's finally found the perfect girlfriend, the beautiful Jenny Johnson (Uma Thurman) -- who just so happens to be a superhero. When Jenny/G-Girl becomes overly possessive, Matt wants to call it quits -- but how do you break up with a superhero?

A scorned woman, Jenny/G-Girl unleashes on her ex the full fury of her super-powered wrath as she sets out on a no-holds-barred mission to bust up Matt's budding romance with his co-worker Hannah (Anna Faris).