Gordon Smith (David Arquette) is an offbeat mailman who has never met a dog he couldn't handle. When he offers to baby-sit James (Angus T. Jones), the young son of his beautiful neighbor Stephanie (Leslie Bibb), he's hoping she'll return his romantic interest. Gordon meets his match: a crime fighting super dog who has just escaped from a witness protection program with local mobsters and his owner FBI agent (Michael Clarke Duncan), in hot pursuit.