Somewhere in Europe, mercenary and former marine D.C. (Stevenson) and his team are hired by the opaque Hunt (Wadham), for a mission to act as protection when Hunt goes into a dangerous countryside, infested with insurgents and other threats. While they reach the destination safely, the nasty surprises don't take long to start coming. Turns out the complex is an underground Nazi bunker, and going by the room of corpses, not one entirely abandoned. One of the bodies turns out to be alive, but appears to be in a catatonic state, so is no help. The team soon come under siege, their perimeter counter-measures effectively proving useless against an enemy that can appear and disappear at will, and they start getting picked off in gruesome ways. What is the real purpose of Hunt's mission? And why is someone - or something - apparently so dead-set against it being completed?
For a small budget film - about 1.2 million quid - this is an impressive piece of work, not trying to stretch beyond its budget or its means, but delivering decent performances from people whose names you mostly may not know, but whose faces should be familiar. The film doesn't hold back too much information, letting it out at the right pace to sustain interest throughout, and when you finally see the enemy they're facing, there's no doubt they're a creepy bunch of... Well, it's probably better to watch it knowing not too much. The director described it as "siege horror," and that's a good summary: it feels somewhere between Assault on Precinct 13 and Dog Soldiers, with the group sinking slowly into a morass as they have to face the reality of their situation. The visual effects are a nice mix of physical and the digital, though the convenience of the machinery at the film's core, and its sense of dramatic timing, does stretch credulity just a tad. However, as a brisk, no-nonsense slab of dark action, it's solidly entertaining.