Mel Gibson's return to acting (it's been eight years since Signs) is a welcome sight. His performance as Tom Craven,a Boston homicide detective whose 24-year-old daughter (Bojana Novakovic) is shotgun-executed before his eyes, shows his movie-star shine hasn't dimmed. The years of boozing and accusations of anti-Semitism have left Gibson,54, looking thicker and worry-creased. But his acting has deepened. Too bad his comeback vehicle springs so many leaks. Edge of Darkness, the Americanization for short attention spans of the award-winning British miniseries from 1985, is a mixed bag even with the same director, Casino Royale's Martin Campbell. The plot complications involving nuclear waste and political maneuvering have been trivialized beyond all meaning. But watching Gibson in a revenge fantasy feeds all my needs for a bloodlusting B-movie feast.