Blood, mayhem, and plot twists as shocking as its imagery explode across the screen in The Cabin in the Woods (2011), a horror film that manages to be complex and thought-provoking even as it gushes at the seams with gore, pain, and hideous death. Joss Whedon and his fellow director wanted to satirize the horror genre and restore it from a slough of pointless torture porn, and largely succeeded.
The opening shot of the movie shows two professional men talking about which "facility" is most likely to "succeed", with the Japanese likely coming in first and the Americans second, with no further details given. The film then continues as an apparently "ordinary" horror flick, with five teenagers heading off for a weekend at a remote woodland cabin. The party consists of two girls and three boys, one of whom, Marty, appears on the scene smoking marijuana (which is important to the plot later).
The action cuts back and forth between the teenagers and the facility as the film develops. The workers at the facility reveal that the teenagers have been drugged by various means, without offering more details. The teen vacationers encounter a stock character "redneck gas station attendant" who warns/threatens them with their impending fate. They drive on nevertheless and start a game of "truth or dare" at the cabin, while the facility workers watch with great interest.
One of the girls triggers the release of a family of "redneck zombies" by reading the Latin inscription from a diary in the basement, though they do not realize this immediately. The teenagers also start acting oddly and very lustfully, with exception of the pot-smoking Marty, who remains his usual self. The zombies attack one couple as they start to have sex in the woods, and after one teen is killed, the others try to escape. However, they are blocked by obviously high-tech means - explosives collapsing a road tunnel, a force field, and so on.