Just before Halloween, three young brothers alone in a big house are menaced by three escaped mental patients who have murdered some traveling circus clowns and taken their identities.

A sociology instructor finds her new teaching duties at a private college interrupted by the presence of a killer.

After she misses her train, a young woman is forced to hitch a ride back to town. After managing to get away from a lecherous trucker, she is given a ride by a good-looking but somewhat mysterious young man, who she comes to suspect may be a dangerous escapee from a mental asylum.