PROPELLED by exotic paraphernalia, a horse-drawn contraption unfurls in the midst of contemporary London. This arcane "imaginarium" offers theatrical magic—and perhaps something more—to any bystanders willing to step right up and take a chance. At the center of the underconceptualized The Imaginarium of Doctor Parnassus is Christopher Plummer as Doctor Parnassus, a con man with astral gifts. Assisted by his daughter Valentina (Lily Cole) and frontman-of-all-trades Anton (Andrew Garfield), Parnassus invites the audience to slip through a silvery mirror into realms where dreams come true.

After 15 minutes of the sort of visual opulence we have come to expect from the staggeringly gifted Gilliam, whose gifts to cinematic folklore include Time Bandits, Brazil and The Adventures of Baron Munchausen, not only does one player, Heath Ledger, tragically disappear, but Gilliam himself seems simply to have run out of ideas. A pity too, since the late Ledger adds charismatic focus to the film's first hour, playing a charming ne'er-do-well who joins up with the imaginarium troupe.

Gilliam has enough invention and burnished nostalgia for 19th-century sleight-of-hand to seduce us for a half-hour. The rich textures of silvered mirrors, velvet kimonos and twinkling carnival lights resonate deeply. Ledger is resourceful enough, vocally and physically, to hold us for another half-hour. What a loss. It is to Gilliam's credit that he turns necessity into clever advantage, enlisting three other actors—Johnny Depp, Jude Law and a particularly engaging Colin Farrell—to fill in as dashing "other Tonys." But the blame for this film's limp and tiresome final hour cannot be laid at Ledger's grave. The failure belongs to writer/director Gilliam.

The film hobbles along on one of the oldest scenarios in the book. As the weary Parnassus, Plummer is a magnificent ruin, face full of hollows, depths and nuance that transform the old carnie into something almost Shakespearean. As his nemesis Mr. Nick, Tom Waits (in black bowler, omnipresent cigarette and pencil mustache) is obviously having a lot of fun. These two, it seems, have been engaged in a tired Faustian bargain for millennia. Parnassus agreed to sign away his daughter on her 16th birthday in exchange for a new life, new youth and a chance for love. Well, that was 16 years ago, and now the devil has come calling.

Along this well-worn path to perdition, the screen bulges with Gilliam signatures, including animated cloudscapes, swirling flatulent fairies and giant heads that break in half, spilling forth more heads (see any episode of Monty Python for refresher). Every hackneyed sight gag of British burlesque is here, including a chorus line of policemen in stockings and high heels, for chrissakes. We've been here before, Terry! And the recycled magic simply fails to work. Given his enormous legacy, I can't help but wonder why Gilliam felt the need make this tarted-up bit of cold turkey.

Amid the clutter and chaos of this creaky tale—ironically, one of the film's self-proclaimed subtexts is that of storytelling, and the fabulous realm of the imagination that can eclipse the real world—there are some momentary gems. As Parnassus' devoted go-fer, Andrew Garfield is a remarkably adroit actor. Passionate and smart, he adds incalculable energy—much-needed energy—to the film's early scenes. Lily Cole adds plenty of fire to her part as the budding girl/woman who begins to fall for the bad boy Tony.

Gilliam seems to have lost his way rather abruptly with The Imaginarium. We never find out what the imaginarium is, why the worlds through the looking glass are sometimes glorious, sometimes nefarious. Every moment of the film's second hour appears to be an unrealized vignette, a gleam in Gilliam's eye that devolves into nothing more than a speck of dust.

THE IMAGINARIUM OF DOCTOR PARNASSUS (PG-13; 122 min.), directed by Terry Gilliam, written by Gilliam and Charles McKeown, photographed by Nicola Pecorini and starring Christopher Plummer, Heath Ledger, Johnny Depp, Colin Farrell and Tom Waits, opens Friday at the Del Mar Theatre.

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