An inevitable idea: a working man (Michael Keaton) who can't meet all his professional and family responsibilities has himself cloned. It works so well having one copy of himself to take charge of matters at the office that he makes another copy who takes care of the home front. Pretty soon, different aspects of Keaton's personality are emphasised in the different clones: the labourer becomes a macho creep and the domestic god becomes rather feminine. A third clone, struck from the duplicates instead of the original, becomes like a photocopy of a photocopy: inferior. Multiplicity is a timely comedy should be better than it is, but special-effects requirements are so labour-intensive that most scenes feel stiff and leaden. Keaton is good in all four parts, and in certain gee-whiz effects scenes, where he even high-fives himself, he pulls off a minor miracle or two. (Of course, a kid did the same thing in Disney's 1998 remake of The Parent Trap.) --Tom Keogh