There’s no denying the sourness, misanthropy and existential agonies of the Joel and Ethan Coen’s work, particularly when they’re swinging for the fences (see: Miller’s Crossing, Fargo, A Serious Man, No Country For Old Men, Inside Llewyn Davis). In bland, Photoshopped Hollywood, they are justifiably prized for being bilious and quirky. They are not, however, infallible.

Their latest, Hail, Caesar! mines a shallow vein: Hollywood moviemaking, a milieu handled much more knowingly and more wittily elsewhere. Under this movie’s Technicolor fantasia veneer, it’s still an angstful, questioning thing all wrapped around an absurd plot about the kidnapping of a dimwit movie star. This time, the barbed-wire bitterness comes sugarcoated in splashy throwback musical numbers that salute the glory days of Gene Kelly’s On the Town dance sequences and Busby Berkeley’s swimming extravaganza numbers in Million Dollar Mermaid.

Hail, Caesar! is kinda sorta inspired by the real life exploits of mobbed-up MGM executive and “fixer” Eddie Mannix (Josh Brolin, who owns the movie by being real and grounded). From MGM’s inception right through to the early ‘60s, Mannix got paid a lot of money to clean up the images of scandal-prone stars like Clark Gable, Ava Gardner and Lana Turner. Fun fact: The real Mannix, who was played by Bob Hoskins in the mucked-up 2006 movie Hollywoodland, may or may not have been involved in a plot to murder George Reeves, TV’s Superman, who was messing around with Mannix’ wife.

This movie’s Mannix spends his days and nights away from his apple pie wholesome wife (Alison Pill) and routinely confesses to a priest that he’s breaking his promise to his wife to quit smoking, all the while mopping up the potentially career-ending messes of Capitol studios stars — including an aging megastar (George Clooney channeling Robert Taylor) who up and vanishes just as he’s about to finish shooting a Quo Vadis-meets-Ben Hur biblical epic. Then there’s a gangly Roy Rogers-type singing cowboy star (a fantastic Alden Ehrenreich) who exasperates the George Cukor-like director (Ralph Fiennes) of a sophisticated comedy Merrily We Dance because he cannot act a lick. Then there’s the randy bathing beauty (Scarlett Johansson), pregnant out of wedlock, whose New Yawk accent is meant to make her this movie’s “Lina Lamont” from Singin’ In the Rain. Meanwhile, a pair of yapping gossip columnist Hedda Hopper harpy twins (both played by Tilda Swinton) are out to expose the stars’ underbellies while members of a secret society of disaffected Marxist screenwriters called “The Future” hold Clooney hostage in a Malibu coast manse.

Universal Pictures

Universal Pictures

With its allusions to long-ago movies, stars and even technicians (e.g. matte artist Albert Whitlock), this is the Coens at their most precious, inside joke-y and, frankly, tiresome. It’s also a film of glaring missteps. Since they’ve gone to so much trouble, with cinematographer Roger Deakins shooting on film and costume designer Mary Zophres batting it out of the park, you’d think the brothers would have kept their end of the bargain. Come on, nobody in ‘50s Hollywood was making ‘30s-style drawing room comedies like Merrily We Dance. Nobody at an MGM-level studio would have let it slip by that in Channing Tatum’s hilariously homoerotic song-and-dance number “No Dames,” he visibly forgets to mouth one of the words to his prerecorded track, he isn’t really tap-dancing and, when he removes his hat, his locks are a mop, not a lacquered-down helmet of hair required back in the era when movies were about perfectionism, not realism.

Of course, any criticism of Coen brothers movies invites the wrath of their diehard apologists. But look, for all its “Hooray for Hollywood” sparkle and highly welcome down-with-Hollywood bile, this dream machine blows its gaskets with too many flat non-scenes, stale jokes and pointless cameos.

Hail! Caesar