Dennis (Simon Pegg). a slightly overweight guy, leaves his pregnant fiancee Libby (Thandie Newton) on their wedding day only to discover five years later that he really loves her.In a bid to win her back he under goes a tough fitness regieme in order to prepare for the London marthon to prove that he is not a quitter.He claims he will win the marathon and in doing so he will win back Libby's heart while making her relaise that her new man is wrong for her.With an all start cast including Simon Pegg, Thandie Newton,Hank Azaria, and Dylan Moran. And David Schwimmer releases his first length feature film for the big screen after directing a handful of projects, which include episodes of Friends and Joey, for television.