To get over his last serious girlfriend, Matt Sullivan (Josh Hartnett) turned to sex. Lots of it. But Matt realised that he needed to go further; to go where no man has gone before. No sex. Whatsoever. For 40 days. That's tough at the best of times, but for Matt it seems impossible: he's just met the woman of his dreams (Shannyn Sossamon) and bets are out that he won't make it. Will he hold on? Will she hold out?