A group of young hippies go camping accompanied by an uptight, sexually repressed, middle-aged chaperone. She is envious of the youngster's liberated ways and doesn't trust one of the young men.

A group of young hippies go camping accompanied by an uptight, sexually repressed, middle-aged chaperone. She is envious of the youngster's liberated ways and doesn't trust one of the young men. Then the group is plagued by a series of vicious knife murders.