AN OLD MAN, the devil, and a midget; a traveling circus that promises to bring the imagination to life... Terry Gilliam's at it again. But The Imaginarium of Doctor Parnassus' immediate distinction is not that it was directed by Gilliam (Brazil, Twelve Monkeys, etc.)—it's that it's the last movie to appear on Heath Ledger's IMDB page. Doctor Parnassus stars Ledger as Tony, a shady businessman who's rescued from near death by a passing traveling circus. The circus, run by one Dr. Parnassus (Christopher Plummer), boasts a magical "Imaginarium," a gateway to a world that's molded by the imaginations of all who enter.

Dr. Parnassus is a miserable, incoherent old drunk who years before agreed to trade his firstborn to the Devil (Tom Waits!) in exchange for immortality. His daughter, Valentina (Lily Cole), is about to come of age, and the Devil's ready to cash in—desperate, Parnassus makes one final bet: If Parnassus can win enough souls to the side of art and imagination, in the face of the Devil's temptations, Valentina will be spared. Parnassus, et al., embark on a frenzied bid to shunt prospective souls through the Imaginarium, aided by the smarmy Tony's huckster charms.

Gilliam salvaged enough of Ledger's performance that Tony's character is grounded in the real world—it's only in the world of the Imaginarium that he's replaced by actors Jude Law, Johnny Depp, and Colin Farrell, thanks to a tweak to the plot (when you go inside the Imaginarium... your face changes! Sure, okay). Ledger's death necessitated this workaround, but every time Depp or Farrell's face pops up, it's an unwelcome reminder not only of Ledger's death, but that these actors are only present thanks to this fairly flimsy last-minute workaround.

Doctor Parnassus' first half has a low-key, character-driven appeal—the rickety charm of Parnassus' cheap costumes and grimy circus-cart is somehow more compelling than the computer-generated whimsy found inside his Imaginarium. But the higher the stakes are, the more the narrative flags, and the relationships that matter in the film's first half are abruptly jettisoned in the second in favor of a visually and thematically incoherent onslaught of CG, making it hard to stay invested in the eventual, vaguely baffling outcome.