Prom Night (1980 Film) - Plot

Plot

11-year-olds Wendy Richards, Jude Cunningham, Kelly Lynch and Nick McBride play hide and seek in an abandoned convent. 10-year-old Robin Hammond joins them but they start teasing her by repeating "Kill! Kill! Kill!". She backs into a window and falls onto panes of construction glass, killing her. The children make a pact not to tell anyone what happened, but a mysterious figure has apparently witnessed the event while a known rapist is blamed for Robin's death and arrested shortly.

Six years later Robin's family attend her memorial on the anniversary of her death. Robin's teenage sister and brother, Kim and Alex, are also preparing for the school prom to be held that evening. Their parents will also attend, as their father is the school principal.

Kelly, Jude and Wendy receive threatening phone calls, while Nick misses the call intended for him. Kim and her boyfriend Nick will attend the prom together. Jude is asked by goofy jokester Seymour "Slick" Crane who she meets by chance that morning. Kelly will go with her boyfriend Drew Shinnick. He is preoccupied with having sex with her that evening, despite her objections. Nick's ex-girlfriend, the beautiful but scheming Wendy, has no date so asks the school rebel, Lou Farmer. She devises a scheme with Lou to embarrass Nick and Kim.

In the change room after gym class, Kim and Kelly discover the locker room mirror severely cracked and a shard missing. The sex offender blamed for Robin's death has escaped and Lt. McBride, Nick's father, investigates. During the senior prom Kim and Nick perform a dance number to impress Wendy who had insisted Nick would be getting back with her after the prom. Kelly and Drew make out in the school changing room, but Kelly refuses to continue to full sex. Drew angrily leaves. As Kelly gets dressed, a masked killer slits her throat.

Jude and Slick have sex and smoke marijuana in his van outside school grounds. However, they are being watched by Kelly's killer, who kills Jude by stabbing her throat. Slick brawls with the killer while attempting to drive away. The killer escapes from the van as it tumbles off a cliff and explodes, crushing and burning Slick to death in the flaming wreckage. McBride, staking out the prom, is informed that the sex offender blamed for Robin's death has been caught. He is relieved and ends his scrutiny of the event.

Wendy is confronted by the killer in the bathroom and is chased through the school. After evading the killer several times she stumbles upon Kelly's body and, distracted, is hacked to death with an axe (offscreen). Kim and Nick prepare to be crowned prom king and queen. Wendy's plan is put into action by Lou and his lackeys who tie up Nick with Lou taking his crown and assuming his position back stage. Thinking he is Nick, the assailant sneaks up behind Lou with the axe and decapitates him.

Lou's head rolls onto the dance floor and sending the panicked partygoers fleeing in horror. Kim finds Nick and frees him. As they prepare to escape, they are confronted by the killer who attacks Nick. Kim eventually grabs the killer's axe and hits him on the head with it. As Kim and the killer stare at each other for a moment, Kim realizes who he really is. He runs outside where the police have arrived. As McBride tries to shoot, the killer, then falls to the ground. The killer is revealed to be Alex, who tearfully tells his sister about how he had witnessed Robin's death before dying in Kim's arms.