Horror author Atwater Bridges is so popular that his hometown has been named     after him. A reformed junkie from New York arrives in Atwater Commons to take    a class in criminal investigation and winds up unearthing corpses of             supposedly fictional characters from Bridges' best-seller, Dirt Boy.     That's just the beginning of the surprises in this inventive low-budget        thriller with darkly comic undertones.                                         Jay Frasco---USA---2001---84 mins.