Constantine is an exorcist, a fully fledged bum, and a moral muddle. Most of all, he is Keanu Reeves. He is a good-looking hunk with the gift of “second sight”, which means he can spot demons dressed as bankers, and the world is squirming with them.

Armed with a customised gold crucifix (which fires sacred bullets), he blasts his way through the pinstripe brigade and recovers in the sewers. He has died once already in a suicide attempt. His ticket has been punched by the Devil (the übercool, white-suited Peter Stormare). But there’s a slim chance of salvation if he saves a sceptical police officer (Rachel Weisz) from giving birth to the son of Satan.

If Keanu slaughters enough ghastly demons he might even buy his way into Heaven. Tilda Swinton’s twisted crook — aka the Angel Gabriel — cackles at the hare-brained joke. It’s impossible to explain this expensive and preposterous film without sounding slightly insane.

The special effects are pure Matrix: slow-motion explosions; orangey filters, black suits, strange mirrors, floating shards of glass, extras who spend most of their screen time sizzling in sulphuric acid. The philosophy is carefully pruned from the D C Comics Hellblazer strip. But I would seriously question its point.

Explore Film

• Film Reviews

• Trailers

• DVD

• London Film Festival

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010