The film opens in a recording studio, where singer Billy "Eye" Harper is in a session working on a few tracks with his band and his girlfriend Lynn Starling, also a backup singer. After he finishes the recording, Billy and the rest of the band leave. Despite trying to record her own vocal tracks, Lynn is left to go to the jacuzzi upstairs, after refusing Kevin the recording engineer's offer to join her.
Meanwhile, Billy returns to the studio, where he finds only Kevin and Mary, Kevin's assistant. In an enigmatic move, Billy kills Kevin by slitting his throat and impales Mary on a wall-mounted coat peg. When Lynn returns, she finds Billy smoking some drugs at the recording studio's control panel. Lynn is unaware that Billy has just killed both Kevin and Mary while she was gone. Once Lynn finds out, she is saved by some security guards.
After a brief intermission, it is two years later, where it is revealed that Billy was captured, tried and executed. It is now the “Rocktober Blood Tour Press Party,” and Lynn and the remaining band members are touring as “Headmistress.” A VJ who interviews Lynn asks several questions about the band's tour, as well as Billy's fall from grace, to which Lynn responds by stating that identifying Billy was
> "the hardest thing she ever had to do."
A mysterious figure then appears in a Halloween “death” mask, and tells Chris Keane, the band's manager, to meet in the office. When she arrives in the office, she is cornered by Billy, in the same death mask, who leaves her curled up, and crying on the floor. After that, Billy persistently stalks Lynn, killing people involved with her along the way, but hiding their bodies, to make others think she is crazy by claiming that Billy is after her.
Eventually Honey Bear convinces Lynn to dig up Billy's grave. They find out that Billy is dead, and Lynn assumes that she is hallucinating. The next night, Lynn and the band are getting ready for the show, when Billy reappears and tells Lynn that he is really John Harper, Billy's twin brother, and that she identified the wrong man. John tells Lynn that the people he killed valued Billy more than him, even though he wrote the renowned songs himself. Then John chloroforms Lynn, and the show begins. A prop coffin pops up on the stage, and Lynn is revealed inside. John tells her that his plan is to kill her as the show's grand finale. When John removes his mask, however security rushes in, attacking him with an electric guitar.
John manages to scream out the final lyrics to "I'm Back" before the credits roll.
