Friends of attractive young adults (ofcourse ) wake to find themselves prisoners in a mysterious house without a way of escape. They are each outfitted with accouterments that are new devices attached to the base in the skulls--and also a recording on a tv monitor alarms them of these task. As a way to flee, they must hurt eachother and themselves. The devices collect the chemicals that the brain produces when in pain, as soon as it collects a predetermined amount, the doors will be opened. Neglect to accomplish it with time, and everybody dies.