I HAVE RETURNED TO TELL YOU THAT I LIKE YOUR HAT: Heath Ledger points out Andrew Garfield. IMAGE: Liam Daniel

It’s just Terry Gilliam’s luck that his dreams are often so darn impossible. The 2002 documentary Lost in La Mancha famously depicted his ill-fated production of The Man Who Killed Don Quixote, while Heath Ledger’s death ground The Imaginarium of Doctor Parnassus to a halt. Even though Gilliam was ultimately able to salvage the latter by enlisting Johnny Depp, Jude Law and Colin Farrell as stand-ins, this long-awaited re-team with Brazil and The Adventures of Baron Munchausen screenwriter Charles McKeown is mostly known now as Ledger’s final film.

The late Australian actually plays second fiddle here to Christopher Plummer’s title character, a monk-turned-sideshow maestro who won immortality in a bet with the devilish Mr. Nick (Tom Waits) some centuries earlier. But Parnassus now pushes his luck with a new wager involving his daughter Valentina (Lily Cole), whom a Faustian bargain has destined for Mr. Nick’s clutches. To reclaim her, Parnassus must best Mr. Nick in a race to seduce five mortal souls. Ledger is amnesiac Tony, whom the sideshow troupe finds hanging by a noose under a bridge, rescues and recruits as a barker.

Gilliam adorns the interior of the Imaginarium—which is apparently Dr. Parnassus’ subconscious—with outsized imagery seemingly recycled from his old Monty Python days. Still, one rarely sees such grandiose visuals outside Hollywood films. Gilliam is enthralling as he harmoniously juxtaposes the baroque with the modern, the hand-drawn with the CGI.

Inside the Imaginarium, Depp, Law and Farrell take turns at the role of Tony while sporting matching ponytails, goatees and eyeliner. This lack of continuity is not at all distracting, even though the film goes out of its way to call attention to what Lost Highway and Palindromes got away with. There are numerous signs of Ledger-related script rewrites, such as the part where Depp laments how James Dean and Princess Di will remain forever young. Unfortunately, this probably also explains why much of the plot is utterly nonsensical. And the visuals simply aren’t compelling enough to compensate for the absence of coherence.

Regrettably, Ledger’s final performance is not particularly memorable, and sharing the role with three other actors certainly doesn’t help. Plummer, on the other hand, is mesmerizing. Playing against type (i.e., Charles Muntz in Up), he is unusually animated, whimsical and physical. At 80, Plummer is still light on his feet and at the top of his game. PG-13.