Brad Majors and his fiancee Janet Weiss set out to visit their former science teacher, Dr. Everett Scott. It is a stormy night and they lose their way, just then the car gets a flat tyre. Stranded in the middle of nowhere they make their way towards a light in the distance to seek help. They arrive at a castle. The door is opened by Riff-Raff, the first of several strange creatures they are to meet that evening. Janet gets a feeling of foreboding as she is introduced to the inhabitants of Frankenstein’s home, Magenta, Columbia and Frank-n-Furter.
Frank is in the process of constructing his dream man, a well-built blonde he calls Rocky. He invites his bemused guests into his laboratory to witness the birth of his creation. Eddie, an unwelcome intruder, interrupts the celebration and is swiftly dealt with by Frank.
That night Frank seduces first Janet and then Brad. Rocky fleeing from his creator meets Janet. As they flick through the monitor screen in the laboratory Janet finds Frank and Brad together. No longer consumed by guilt, Janet succumbs to Rocky’s obvious charms.
Riff-Raff informs Frank of Rocky’s escape. A frantic search ensues. Brad then discovers Janet with Rocky. Frank is distraught at the thought of his beautiful creature being defiled by Janet.
Riff-Raff announces the arrival of Dr. Everett Scott who is in search of his nephew, Eddie. Dr. Scott, no longer a science teacher, works for the Government investigating Aliens. He informs Brad and Janet of Frank’s true identity. Frank immobilises Janet, Brad, Dr. Scott, Rocky and Columbia and announces a midnight floor show.
Riff-Raff and Magenta accuse Frank of failing in his mission and announce that the time has come to return to their native planet. The tables are turned, they are the power. Frank is eliminated along with Rocky and Columbia. Riff-Raff and Magenta beam the entire castle back to Transsexual Transylvania leaving Brad and Janet and Dr. Scott behind – surrounded only by the wind.