A sombre-faced Paul Bettany channels the dramatic intensity of Wilson the volleyball in his starring role as a vampire-slaying missionary in Priest, a scattered-brained monster movie with a faux religious twist courtesy of director Scott Stewart and the graphic novel on which the film is based.

The setting is an anachronistic future world that looks like the old west but has guns, sleek high-powered motorbikes and all manner of techno gadgets. And vampires. Lots of vampires.

In this world, as the introductory voice over announces, “there has always been man and there has always been vampires…vampires were stronger and faster but man had the sun.” Humanity defeated the blood suckers when it found its ultimate power: warrior priests who kick ass for the lord.

For a long time humans prevailed but the vamps are back, festering in underground lairs and secretly breeding an army. Enter Priest (Bettany) who, with a crucifix tattooed across his forehead, must defy the orders of the church to track the vampires and send them to hell. This time it’s personal: they’ve abducted his niece and the head John Jarratt-esque vamp, Black Hat (Karl Urban), is using her as bait.

Bettany’s humourless performance forms the steely heart of the film. Sallow, serious and evidently vitamin deficient, Bettany is a stiff plank of wood — the boring guy dragging down the vibe of the party.

The vampires he KA-POWS are closer to Chris Carter than Bram Stoker — freaky swamp-like things covered in slimy fluid. Like Daybreakers there are three kinds of characters: humans, human-like vampires and freaky monster vampires.

The action scenes are the best bits but they’re few and far between, with an awful lot of dull padding in between. There is a drab energy that drags the film feebly along; it’s not sharp, fast or peppy enough to sustain such a mediocre storyline.

“If you’re not committing sin you’re not having fun,” says Black Hat. And that’s the core sin Priest commits: it ain’t fun.

Priest’s Australian theatrical release date: September 8, 2011.