Ask horror fans for a gripe about the state of cinema today and the one you'll get back time and time again is that there are far too many films made with the 15A cert in mind and not enough projects willing to get down and dirty in 18s territory. Well, no one could ever accuse Let Us Prey of going too easy - it's pitch black, nasty and should have gore hounds thumping the armrest in delight. How hardcore? Put it this way, someone is mauled here with a mechanised shoe polisher. That's how first-time director Brian O'Malley and writers David Cairns and Fiona Watson roll.

Shot largely in Galway, but set in a small town Scottish police station over the course of one night, Let Us Prey follows rookie cop Rachel Heggie's (Pollyanna McIntosh) baptism of fire. And brimstone, blood and guts. Joining the local collection of pond life down in the cells is Six (Liam Cunningham), a man whose records show died in 1983. He's not there by chance, and it's not long before he starts his war on the minds of all those around him.

In the pantheon of perfect casting, a special place should be reserved for Cunningham in Let Us Prey. He and follower Dubliner O'Malley had previously worked together on a short film and the decision to get him to play the 'bad' guy here is so inspired that you just couldn't see anyone else in the role. It's one of the best things Cunningham has done, his voice bringing a hypnotic intensity to the character. You'll never hear that Dairygold ad in the same way again.

As for McIntosh, she proves to be an excellent action hero, but backs up the gung-ho with an emotional intensity that's missing from so much of the genre. Her verbal jousts with Cunningham are great and the chemistry between the duo is perfect in its edginess. You'll cheer McIntosh on from the start but are never quite sure if her character will still be among the living by the close. It's that kind of movie; Napoleon Wilson would indeed be proud.
 
O'Malley's next film is to be a claret-free ghost story set in the London Underground. He's shown himself here to be a filmmaker of real promise, so hopefully the wait won't be too long. Until then, give the Devil his due.

Harry Guerin