Prom Night III: The Last Kiss
(1990)

Alex (Tim Conlon) rejects Mary Lou (Courtney Taylor) after she kills three people that had a problem with him, so Mary Lou kills his best friend Shane (David Stratton) and then frames him for all of the murders (even though he was partially responsible for the first three deaths since he buried them in his school’s football field). When she visits him in his jail cell, he refuses her again, so she decides to go to the school prom and kill his girlfriend Sarah (Cynthia Preston), figuring that if she can’t have him, nobody can. He manages to escape his cell and force a police officer to drive him to the school.

At the school, Mary Lou confronts Sarah in the halls and chases her into the gym, and she arrives there at the same time that Alex does. Mary Lou bursts out of the stage floor and seizes Sarah, but Alex begs her not to kill her, instead pleading for her to take him and not harm anyone else. She agrees to it, and they begin to descend into the depths of Hell. However, Sarah goes in after them.

She arrives in a nightmarish version of 1957 Hamilton High, where she makes it to the gym before Mary Lou can kill Alex so he can be with her forever. She temporarily subdues Mary Lou and gets Alex out of there, and they run from zombified students and enter and start up a car. Mary Lou reappears to try and seduce Alex one last time, but Alex drives into her, and the collision seemingly takes them out of Hell.

When they stop by a payphone at a drive-in to call their parents, Alex notices that the payphone only takes dimes. Mary Lou then kills Sarah in a surprise attack, and Alex realizes that he is still trapped in the 1957-style Hell – and can’t do anything about it. Defeated, he screams, “You win! You hear that, you fucking bitch?! You win!” before laughing insanely.

Thanks Tornado Dragon!