In 1991, the Coen brothers’ WWII Hollywood fantasy-farce “Barton Fink” swept the prize table at the Cannes Film Festival, earned three Oscar nominations and made major players of John Turturro and John Goodman.

Their new dream factory satire “Hail, Caesar!” is set at the same fictional Capitol Pictures studio a decade later. This time the production is crammed with established stars, packed with Busby Berkeley aquatic ballet, Gene Kelly dancing, elaborate musical numbers, platoons of extras dressed like Roman soldiers, and a blockbuster budget.

What it has much less of is interest. The Coens have reportedly had the film on a slow boil since 2004, and it reaches theaters disappointingly overcooked.

Taking place in 1951 Tinseltown, “Hail, Caesar!” is a cornucopia of film-within-film sequences. It wanders from sound stages to projection rooms to the editing suite, where the person snipping the celluloid (Frances McDormand, sharing walk-on cameos with veterans like Dolph Lundgren and Christopher Lambert) can be strangled if her scarf slips into the gears. Rather than adding up to an interwoven story line, it’s a long, rambling shaggy-dog story. I know there is a dog in it, anyway. What they intended this confusing tale to be overall, I have no idea.

George Clooney, who has become the Coens’ go-to guy for pinhead roles, plays Baird Whitlock, star of a ponderous sword and sandal religious epic titled “Hail, Caesar! A Tale of the Christ.” After a movie stand-in (Wayne Knight) slips a mickey into a chalice Whitlock guzzles for the camera, the dimwitted star vanishes, halting the studio’s prestige film of the year. Locating him falls to Capitol’s official problem solver, Eddie Mannix (Josh Brolin in low-key form). Whether he’s bribing police to ignore a bawdy starlet posing for naughty photos or running a half-comic meeting with a priest, a minister, an orthodox monk and a rabbi on “Hail, Caesar’s” theological core, he keeps the studio out of scandal and profitable.

Mannix, an essentially decent fellow who daily confesses to his priest whether he has sinned, is wildly overworked, putting out fires at a rate that keeps him from ever visiting his family. He’s committed to the job because he loves the fantasy world that solves life’s problems with make-believe. When the Lockheed aircraft corporation offers him a much better package to become their fixer-in-chief, he’s deeply conflicted. His studio delivers happiness. Lockheed delivers the newly invented hydrogen bomb.

Mannix may be the film’s leading character, but he is hardly the main focus. The Coens’ way-back machine fills the story with players from golden age Hollywood, following them across the story’s sidelines like a film buff chasing idols with an autograph book. Scarlett Johansson paddles across the screen as an Esther Williams-style swimming star whose out-of-wedlock pregnancy Mannix hopes to obscure. Ralph Fiennes delivers some verbal slapstick as a posh British director battling to save his sophisticated drama from the star who has been thrust upon it, a gauche singing cowboy (Alden Ehrenreich, whose casting is one of the film’s genuine delights). Channing Tatum dons skintight sailor whites as the dancing star of an all-male Navy musical whose “No Dames” theme song cuts loose into a gender-bending homoerotic boogie the Village People would envy.

If all that added up to a series of consistent punch lines, “Hail, Caesar!” would be a treat. Instead, the Coens allow scene after scene to overstay its welcome. To have Clooney sit on a chair in his centurion uniform and nearly impale himself on his sword is a buffoonish gag at best. Turning it into a running joke is a waste of time. Using Michael Gambon’s silver throat for verbose stop-and-go narration, and master cinematographer Roger Deakins to mimic the Technicolor sheen and varied screen ratios of Turner Classic Movies, is a waste of talent.

I left “Hail, Caesar!” feeling it wasn’t Baird Whitlock who was abducted. Someone kidnapped the plot. The Coens’ 17th film is so far from the high-water mark of their recent work that I wished Eddie Mannix had burst onto the sound stage to save it.