Science-fiction blockbusters are beginning to front some of Hollywood’s most aggressive crusades. Babylon A.D. is a futuristic thriller with Old Testament twists. It’s also a 6,000-mile road trip complete with the most unlikely short-cut since Charlton Heston parted the Red Sea in 1956.

The film begins in an Eastern European slum clogged with gangs of hungry soldiers hawking guns for money. The hero is an unreconstructed beefcake, Vin Diesel, who is offered a mission to save the world. “Save the world?” Vin grumbles as he casually garrottes a Russian soldier on his way home. “Whatever for?” It’s difficult to argue when it rains like a firehose every time one goes for a pint of milk.

Money as ever oils the wheels. Vin might dress like a tramp but underneath all that Boy Scout clobber he is a lethal gun-for-hire, perhaps the best. Before the credits stop rolling Vin has extinguished a couple of extras with extreme prejudice, rustled up a delicate rabbit stew, and admitted in his gravelly voiceover that he has to die to save the girl, the world, his bank balance, and possibly his soul, but not necessarily in that order.

A rich terrorist (Gérard Depardieu at his greasy, seedy best) offers Vin a fortune to smuggle a sexy young virgin, Aurora (Mélanie Thierry), from a convent in Outer Mongolia to a penthouse suite in New York. The more the film tries to explain, the more ridiculous the reasons. It’s mission impossible. America is a neon Sodom and Gomorah. The rest of the world is a war-torn slum populated entirely by starving refugees.

There isn’t a single honest character – with the exception Michelle Yeoh’s high-kicking nun – between Depardieu and the deep blue sea. Squads of psycho acrobats have their necks broken by Diesel on dance floors or polar ice caps. The director, Mathieu Kassovitz, has a great eye but a terrible grip on the story. He shamelessly – and rather brilliantly – clones the end-is-nigh misery of Alfonso Cuarón’s glum arthouse hit Children of Men. He steals clever tricks from every sci-fi classic since Metropolis. And the landscapes are refreshingly damp and grainy.

But the sexual tension between the two squabbly heroes is just a quick squeeze of one of Diesel’s admittedly marvellous pecs. Despite plenty of shrieks, Aurora is a wispy and frustrating blank. Her divine powers are endlessly flagged up by a chorus eternally stuck on two lines of Handel’s Messiah.

But stars as butch as Diesel have limited appetites for mystery and arthouse gloom. The lucrative business is the medley of awesome stunts, and the visceral beatings that Diesel dishes out. Hitching a ride on a pirate nuclear submarine is a shard of Boy’s Own magic. It’s utter codswallop, yet enjoyable if you unplug your brain.

12A, 90 minutes

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