Mary, a beautiful blonde pre-med student, makes a sexy video which she texts to her boyfriend Bob. The next night, on picking her up from school, Bob denies having received the video, and Mary wonders who may have received it instead; Bob teases her, suggesting it may have been a deranged serial killer.
Meanwhile, a sadistic serial killer, his latest victim’s body on the floor in front of him, watches the video repeatedly and decides to pursue Mary as his next target.
Later that night a provocative Mary awakes to, only moments later, find herself haunted by the feeling that someone is outside her window, watching her; and she’s right.
The next day Mary relays her fears to Bob, who is dismissive of her concerns, and continues to tease her in his typical carefree manner. But even then, as she is at ease having lunch with Bob, Mary is already the next mark of a vicious sociopath, who continues stalking her.
Later that evening, Mary studies well into the night for her A & P final; suddenly, the lights go out in the hallway, and Mary decides it’s time to leave. Remaining vigilant Mary gathers her things and leaves the classroom; upon reaching the stairwell Mary realizes: she is not alone. The deranged killer that has been stalking her every move is closing in for the kill.
Mary drops her books and runs, seemingly frantically up the stairs, where she trips and falls hard, before slowly crawling to her feet; giving the killer just enough time to reach his prey. As the killer savors the moment, examining his target, as she is seemingly frozen helpless in place in front of him, Mary slips a knife from under her skirt, and expertly stabs him, with the precision of an accomplished surgeon, severing major blood vessels and collapsing his lungs. The killer, armed only with the garrote intended for Mary and covered in the blood of dozens of previous victims, falls helplessly down the stairs; he is dead before his body comes to a stop at the bottom of the stairwell landing.
On arriving home Mary secures the garrote, her trophy, in a dresser drawer, along with similar trophies taken from at least a dozen prior kills: poisons, knives, guns, plastic, etc. The next day Mary is content: she has freed the world of her latest target, she has passed her exam with flying colors, and she has already set in motion her next kill, as she teases Bob again at having not received her latest sexy video… “Hmm… I wonder who got this one?”