Five young people take part in an endurance test whereby they have to stay together in an isolated old house for six months in order to collect a $1 million prize - which is forfeited if even one of the subjects leaves.
This claustrophobic horror movie taps into a specific set of cultural phenomena from the early 2000s: the sinister byways of internet; Big Brother-style reality TV; the Blair Witch docu-aesthetic; celebrity exhibitionism.
The traditional old, dark house setting is dotted with webcams which swivel to catch the action, roping the audience in on the tormenting of the characters. This escalates from withholding food and heat, to cruel psychological tricks that inevitably lead to gruesome violence.
The well-delineated, mismatched characters (three blokes, two girls) react to the situation in wildly different ways, but all wind up reaching for weapons.
Edgy emotion enters into unsettling scenes as the cast try to concentrate on their plight, but keep being distracted by the cameras and the problems simmering within the group. Towards the end the bodies pile up, but its the early stretches that are far creepier, making great use of classic nerve-fraying horror business.
Its an effective, gory but traditional psycho-stalker movie raised above average by inventive scares early on.