- Main article: Characters
- The Old Queen
- Steve Majors
- Lord De Lordy
- Riff Raff
- Ray Ammbo
- Sonny Ammbo
- Judith Brankmire
- Janet Majors
- Mary Lou
It has been a decade and a half since the events of that fateful evening chronicled in The Rocky Horror Picture Show. In the eternal night of the planet Transexual in the galaxy of Transylvania, General Riff Raff is found mourning over the coffin of his dead sister Magenta, and his mental disposition has not improved overtime. No one knows it was he who killed her in a fit of jealous rage over an alleged liaison she had with Lord de Lordy, second in line for the Old Queen’s Royal Deck chair after her son Frank N Furter. Magenta’s current deceased status, though, has apparently not put much of a damper on their “relationship.” Riff is summoned before the Great Furter herself, the Old Queen, who commands that he return to Earth and bring back her son Frank so he can assume his rightful place as her heir before she dies. It is apparent that Magenta’s murder isn’t the only one that Riff is hiding.
Meanwhile on Earth, Steve Majors, an agent for the Bureau of Investigation Into UFOs, has made a startling discovery. While reading an old file labeled “The Denton Affair,” he has uncovered the fact that the popular movie The Rocky Horror Picture Show, was based on actual events that happened to his older brother and his fiancee fifteen years ago. He confronts his boss Ray Ammbo with this information, plus the fact that there are still Transylvanians on Earth and that they have at least one safe house, hidden away in Fresno. Ray, whose son Sonny is a teen pop star with the song “The Moon Drenched Shores of Transylvania,” knows all this already, as he is obviously a collaborator with the Transylvanians. But he knows that the safe house has been abandoned for some time, so he lets Steve go and investigate in order to get him out of his hair.
Driving cross-country to Fresno, Steve is contacted by fellow agent Judy Brankmire, with whom he went to Denton High School. Judy has already arrived at the safe house and is waiting for Steve in order to begin their investigation. While waiting, she decides to freshen up with a shower, not knowing that the stall is a disguised transducer, a Transylvanian space and time teleporter. As she is soaping up, Judy is accidentally transported to Transylvania as Riff Raff teleports to Earth. Of course, the running shower soaks Riff. Judy arrives on Transylvania covered only in a bit of bubbles and is met by Lord de Lordy. The two are instantly smitten with each other.
At the Fresno safe house, Riff Raff has been alerted to Steve’s impending arrival by a phone call from the agent. Tricking Steve into believing that he is Judy’s brother George, Riff Raff bundles the agent into the transducer to Alaska. Riff then heads for Denton, only to discover that a housing development, Happy Homes, has been built on the land where the castle once stood. Returning to the local Holiday Inn, where a transducer has been hidden, he encounters Janet Majors, nee Weis, who is so far derelict that neither of them recognizes the other. Riff then teleports to the past.
Stranded at an Alaskan Holiday Inn, Steve takes a stab at figuring out the transducer’s controls, teleporting into Ray Ammbo’s office, joining Ray, Mary Lou, Sonny and the recently arrived Lord de Lordy and Judy, who are on the run from the Old Queen who has accused them of sedition. The group crams themselves into the transducer and teleports to the Denton Holiday Inn shower that Riff just used and then follow him back in time.
Everyone arrives outside the House but before Riff or anyone else can get inside to stop the younger Riff from murdering Frank, a firefight erupts between all the parties. Steve is knocked unconscious in the melee and Riff kills Lord de Lordy and Judy. The House takes off as it did at the end of the first film and the Old Queen’s soldiers are killed. Ray is also killed, but not before revealing that he is actually Sonny’s adoptive father – his real parents are Janet and Frank N Furter, making him next in line for the Transylvanian throne.
The Old Queen dies and Riff Raff pledges his allegiance to the new ruler, Sonny. Riff, Sonny, Janet and Mary Lou head back to the present and Transylvania for Sonny’s coronation. Forgotten, Steve regains consciousness. Heading back towards his childhood home, Steve tries to convince his mother that he is her son from the future. As she calls the cops, Steve shouts a warning that the Transylvanians are infiltrating the country and to “Keep watching the showers!”.