As the seven sorority sisters—Kate McNeil, Vicki, Liz, Jeanie, Diane, Morgan, and Stevie—gathered to celebrate their graduation at their sorority house, the atmosphere was thick with excitement and underlying tension. Their joyful celebration was abruptly interrupted by the overbearing Mrs. Slater, who denied their request for a graduation party. Frustrated and pushed to their limits, the girls concocted a daring prank to get back at Slater: they planned to pilfer her walking cane and, under the duress of a gun, forced her to retrieve it from the pool. However, things took a tragic turn when Vicki's shock led her to inadvertently shoot Slater in the chest. In the ensuing panic and desperation, the sisters made the shocking decision to conceal the body in the pool.
As the night progressed, an ominous presence began to unravel the festivities. An unseen figure, armed with Slater's cane, started to exact a brutal revenge on the unsuspecting partygoers. With the chilling realization that turning on the pool lights would expose Slater's corpse, the sisters scrambled to contain the horror. Stevie braved the dark basement to cut the power, but her mission ended tragically when she met her end at the hands of the unknown assailant.
With chaos engulfing the night, the remaining girls were plunged into fear-induced hysteria. Convinced that Slater might somehow still be alive, they embarked on a frantic quest to locate her. Morgan's nosiness led her to Slater's room, where she was horrified to discover the dead body tumbling from the attic hatch. As they plotted to hide the corpse in a nearby cemetery, their plans devolved into more violence and chaos.
In the attic, Kate McNeil stumbled onto a horrific scene filled with children's toys and the carcass of a small bird. Then, Morgan fell victim to the killer, brutally stabbed with Slater's own cane. Diane's attempt to discreetly transport the body in the van ended tragically as she too fell prey to the relentless murderer, while Jeanie suffered a fate even more grim.
In a moment of desperate clarity, Katey uncovered a medical alert tag on Slater's necklace, prompting her to summon Dr. Beck, who arrived amidst the unfolding turmoil. Together, they faced the chilling sight of Stevie, Morgan, and Diane’s bodies floating lifelessly in the pool. Meanwhile, Vicki and Liz set off to the cemetery with intentions to hide Slater's corpse, only to seal their own fates as they became the next victims of the vengeful killer.
When Katey and Dr. Beck arrived at the cemetery, they were greeted with horror: the lifeless forms of Vicki and Liz lay alongside Slater's body, which continued to be trapped in the van. What began as a graduation party had devolved into a nightmare of tragedy and despair. As Dr. Beck's nefarious motives unraveled, he compelled Katey to take a sedative, revealing dark secrets including the fact that Slater had undergone illegal fertility treatments that produced a son, named Eric, who had suffered grievously due to his circumstances. With insidious intentions, Dr. Beck planned to use Katey to lure Eric and cover up his own deceitful acts.
Eric's appearance at the scene brought more chaos, as he swiftly took down his father's accomplice. Desperate to defend herself, Katey searched for Vicki's gun only to face the unsettling reality that it wouldn’t fire. Panic-stricken, she stumbled into the bathroom and encountered a gruesome sight: Jeanie’s severed head lay there, a haunting reminder of the horrors that had transpired. Overwhelmed and without a clear way out, Katey fled to the attic for refuge, only to find Eric pursuing her viciously.
In a fight for her life, Katey attempted to defend herself with a series of shots, believing she was armed, only to discover that the gun was loaded with blanks. With Eric's relentless attack bearing down on her, she resorted to using a pin as her final weapon, stabbing him multiple times until he crashed through the attic door, falling to the floor below. Exhausted and hopeful that she had brought the terror to an end, Katey collapsed in relief—only to be jolted by the horrifying realization: Eric's eyes snapped open, his malevolent spirit far from extinguished.
