Robert Lepage ("Le Confessional", "No") is very talented but "Possible Worlds" is very dumb. It's not that the film's concept, adapted by John Mighton from his play, is a bad one, but that Lepage's execution of it is so inept and so annoyingly solemn. McCamus plays his parts monotonously and Tilda Swinton as both a neurology professor and a businesswoman fails to delineate her two characters. Other than the differing hairstyles, they may as well be the same person. Add some scientific mumbo jumbo, some pointlessly exotic sets and a whole lot of pretentious dialogue and you'll wish you were in any world but this one. Starring Tom McCamus and Tilda Swinton. Directed by Robert Lepage. Written by John Mighton. Produced by Sandra Cunningham and Bruno Jobin. No distributor set. Science Fiction. Not yet rated. Running time: 93 min.