A group of eleven young people have been picked to take part in a special ski course, but their excitement soon disappears. Not only is their isolated chalet cut off from the outside world by an avalanche, it also turns out that something is seriously wrong with the three ski instructors. Under the supervision of \u00bbDaddy\u00ab, Dingo and Babeta organise cruel drills, cause tension and turn the youngsters against each other. Food is rationed, weaknesses are exposed, secrets strategically divulged and individual children arbitrarily ostracised or favoured. They perfidiously insist there is one person too many and that this person must be sacrificed by the others. The youths are compelled to make a life and death decision, only then can they return home. The group\u2019s sociogram therefore shifts constantly. The camera\u2019s nerve-wracking dynamics and an unsettling soundtrack heighten the sense of dread. The horror film surprisingly evolves into a sci-fi story. The ski instructors turn out to be aliens who are testing humans for an imminent invasion. With her bizarre humour, Chytilov\u00e1 dissects the mechanisms of oppression and manipulation in totalitarian systems.<\/p>\n