To All a Good Night

During the Christmas vacation at Calvin Finishing School For Girls, a student is killed when she is accidentally pushed over a balcony during a prank. The incident haunts the school and foreshadows a motive for revenge that will resurface two years later. This tragedy sets a dark tone that threads through the present events.

That Friday, five students decide to remain at the school as it empties for the holidays. They plan a weekend gathering with their boyfriends, hoping for a quiet, festive time. That night, Cynthia and her boyfriend are murdered outside the school by a hunting-knife-wielding assailant.

The remaining girls coerce Nancy into giving their housemother, Mrs. Jensen, milk laced with sedatives to help her fall asleep. The plan is meant to keep the house quiet while the others enjoy their weekend. The deception seeds a dangerous path for what follows.

After drugging Mrs. Jensen, the group goes to a nearby airstrip to meet their boyfriends who have flown in on a private plane. They settle in for the night, believing everything is going according to plan. The mood shifts as suspicions rise in the background.

Trisha goes to the kitchen to retrieve beer and is killed by a Santa-clad killer. Tom goes to search for Trisha, but is pursued outside and beaten to death with a rock. The killer buries each body in the school's garden, turning the grounds into a graveyard.

In the living room, Sam and Blake share a moment, unaware of the danger. The killer, wearing decorative armor, shoots Blake and decapitates Sam with an axe. Their bodies are hidden as fear spreads through the house.

Nancy runs into Ralph, the groundskeeper, who ominously warns that something evil is about to happen. The sense of dread thickens as the night wears on. The next morning, Ralph's corpse is found in the woods, confirming his warning was not empty.

Detective Polansky arrives to investigate the chain of murders and urges the students to stay sequestered for safety. That night, Jim, a police officer stationed outside the school, is murdered with an axe. The investigation tightens the net around the remaining survivors.

Leia seduces Officer Dan, then discovers Sam's severed head hanging from the shower head. Dan rushes into the bathroom but is stabbed to death from behind. Leia is left traumatized, dancing and humming as a broken figure.

Melody and T. J. share a kiss under a tree, unaware of the killer above. The killer strangles T. J. with a wire garrote, and Melody flees back inside to seek help, frightened by the night's deadly turn.

The killer in a Santa outfit is revealed to be Mrs Jensen, avenging her daughter's death. Melody reaches the airstrip and begs the sleeping pilot to take her away, but they are killed when the engine starts and the propeller slices them apart. The Santa killer's presence continues to terrorize the survivors.

Back at the school, Nancy is chased by Mrs Jensen to the balcony, where Mrs Jensen falls to her death. A second Santa-clad assailant is revealed to be Polansky, Mrs Jensen's husband, who tries to strangle Nancy but is killed by Alex with a crossbow. Alex and Nancy flee the building together, leaving Leia dancing alone on the balcony.