Filmmaker Neil LaBute, the king of relationship nastiness, is back to his unsparingly acidic form in the jet-black The Shape of Things. Based on a play LaBute wrote, the movie has more of his trademark verbal battles and characters giving into bad temptation.

Dorky college student Adam (Paul Rudd) can’t believe that the beautiful, quirky Evelyn (Rachel Weisz) would ever want to date him. So he thinks it’s only fair to follow through on her suggested improvements to his appearance.

But while his friends (Frederick Weller, Gretchen Mol) see nothing wrong with changing the clothes and the hair, it’s changing the body they bristle at. Long-buried crushes and evil manipulation ultimately come to the surface.

A stunning four-actor show of lust, anger and repression, The Shape of Things is kept from greatness only by how glaringly obvious it is. The conclusion is predictable and not that shocking, so it loses most of the wallop LaBute thinks it has.

But the road to that ending features strong acting all around, namely from Rudd, as convincing a schlub as he is a pretty boy, and Weisz, uncharacteristically evil and so delicious in doing so. The commercially minded Nurse Betty aside, it’s LaBute’s weakest work. But even on a bad day, he’s better than most.