Jack is the story of a 10-year-old boy (Robin Williams) who ages at four times the normal rate and is consequently trapped in the aging body of a 40-year-old. So is the movie a heart-warming tale of a magical manchild who brings out the kid in everyone, or the depressing story of a tormented boy with a degenerative terminal disease? It's both, and it's feeble in both capacities. When Jack celebrates the youthful hijinks of wisecracking 10-year-olds, it's packed with juvenile fart jokes and gauzy sentimentality. When it turns serious, it's a gloomy bore. Considering that Francis Ford Coppola is the recipient of a handsome paycheck for directing Jack, the movie is lazily assembled: If Jack keeps breaking his tiny student desk, why don't they get him a bigger desk? If Dad is a photographer and Mom is a housewife, why are they living in a kajillion-dollar mansion? Where did a few slackjawed kids come up with the architectural skills to build an impossibly elaborate treehouse? Why are the town doctors so matter-of-fact, and even disinterested, when discussing Jack's one-of-a-kind medical condition? If Williams is physically aging so quickly, why has he never had an erection? And finally, why does Coppola allow Williams to constantly slip out of character and fall back on manic Robin Williams antics?