In 2008, a devastating disease called the Reaper virus spreads like wildfire through Scotland. As deadly and nasty in its symptoms as the Ebola virus, the British government makes the decision to erect an enormous steel wall between Scotland and the rest of the island, leaving everyone trapped behind to die. Two decades later, the Reaper Virus reappears, this time in London. Unbeknownst to anyone except the Prime Minister and a few higher-ups, a spy satellite has detected human life in Scotland. They jump to the conclusion that if there are survivors of the virus then there must be a cure. The decision is made to send in a team of soldiers and scientists to bring back any proof of a cure before the government is forced to quarantine London and let millions die.

Leading the team of soldiers is Eden Sinclair (the pretty, but bland Rhona Mitra, Skinwalkers), a one-eyed kick-ass powerhouse who, as a child, was one of the few people lucky enough to make it out of Scotland. Her team is made up of the usual interchangeable characters with Adrian Lester (Primary Colors) the only actor among them to make any kind of an impression. Once beyond the wall, things quickly turn bad as a gang of survivors that have an affinity for Mohawks and overacting ambushes the team. At this point, logic, story and character development are completely abandoned in favor of one over-the-top action sequence after another, climaxing in a fantastic car chase turned demolition derby that would warm the heart of George Miller.

If you couldn't tell by that plot description, there's not an original moment to be found in the entire running time of the film. But being derivative in this particular genre isn't necessarily a bad thing. The last thing anyone expects from a futuristic action flick is a thoughtful meditation on the state of the world. The audience is there to see bigger and better stunts, cooler weapons and crazy villains. Doomsday delivers these ingredients in spades. With shotgun blasts to the head, arrows though throats, decapitations, human barbecues, cannibalism, a killer knight (complete with ancient armor and a mace), surreal music choices and various bodies torn apart with bullets and various sharp implements, the whole thing adds up to the most gratuitously violent and intentionally silly film since last year's under-appreciated Shoot 'Em Up. In fact, one gets the feeling that this film is what a Michael Bay acid-trip might look like.

It is a fun movie; make no mistake about that. But that fun is tempered by the fact that Marshall is capable of so much more than what he has delivered this time around. With Dog Soldiers, his brilliant twist on the werewolf film, he created both stunning action sequences and interesting characters that the audience cared about. His last film, The Descent, was one of the most frightening films to come along since The Exorcist. As with his previous film, he gave us characters with complicated relationships that were far more developed than the horror genre normally provides. That's why it's a disappointment to find this to be such an essentially empty-headed genre exercise.

That nagging little complaint aside, this is a worthy project purely as a kinetic joyride. It's a violent, gory and unpretentious jaunt into hell on Earth that doesn't have a brain in its mohawked, decapitated head. If you can turn your brain down to zero and think of this as a little splurge of junk food in your otherwise healthy cinematic diet, you should find plenty of entertainment value for your money.

Matt Wedge is a writer and film critic living in Chicago.