Benjamin Morgan, Walter Brennan, a wealthy invalid, suspects his second wife, Elizabeth Hall Morgan, Julie Harris, of poisoning him. His daughter Alexandra Morgan, Eleanor Parker, shares his fear and summons her three sisters—Freddie Jessica Walter, Jo Jill Haworth, and Chris Sally Field—to the Morgan farmhouse for Christmas. The homecoming unfolds with a tense mix of suspicion and fragile family bonds as the first storm of winter blankets the countryside with rain and memory.
Upon their arrival, Benjamin calls them to his room and urges them to kill their stepmom before she kills all of them, a chilling order that sets a dark, unsettling tone for the holiday. Elizabeth, meanwhile, begins preparations for a dinner that should feel like a normal feast, but the atmosphere is anything but ordinary. Freddie’s outbursts interrupt the quiet, and a scene of fear and confusion erupts when she screams, clutching a glass of vodka while a shard of glass cuts into her hand. The sisters move quickly to calm her and get her to bed, trying to restore a sense of control amid the mounting dread.
That night, a rain storm roars outside the farmhouse, turning the house into a claustrophobic stage for old resentments and new fears. Jo, exhausted by the reunion, asks to borrow Alex’s car to escape to the local train station, hoping to return to some form of normalcy. As she approaches the car, a mysterious figure in a yellow rain slicker appears, wielding a pitchfork, and Jo is swiftly struck down, gone in a blink of fear and shadow. The storm continues to rage as the sisters try to steady themselves.
Freddie’s problems deepen; she drinks heavily and eventually slips into a warm bath, where danger lurks as the intruder returns and drowns her in the tub. The next morning, Chris finds Freddie’s body in the tub, and a fresh wave of accusations washes through the house. Alex accuses Elizabeth of poisoning Freddie, while Benjamin briefly leans toward thinking Freddie might have taken her own life. Chris tries to call the police, but the line is dead, severing a fragile link to outside help.
Alex ventures into the woods to use a neighbor’s phone, all the while being shadowed by the figure in the yellow slicker. She eventually returns to the farmhouse, only to discover Jo’s body in the barn. Elizabeth emerges from outside, urging Chris to come with her, but Chris balks and locks the door, discovering Benjamin dead inside. The chilling realization settles in as Chris screams and flags down a passing car—driven, as it turns out, by Alex herself.
As the truth comes to light, Chris explains that Elizabeth has murdered everyone, but Alex shocks everyone by admitting she is the actual killer. Fueled by childhood persecution fantasies and a deep-seated resentment of her siblings, Alex had meticulously framed Elizabeth as the killer to take control entirely. She then attacks Chris with a tire iron, and Chris’s body disappears down the hill, out of sight.
Hoping to complete the frame-up on Elizabeth, Alex invites investigators to accompany her to the farmhouse. Yet her plan unravels in a frenzy of guilt and hysteria when she sees that Chris is still alive, throwing her into a panic. The police take Alex away, leaving Elizabeth to tend to the Morgan farmhouse alone, a chilling quiet settling back over the place where a family’s secrets finally came to light.
