In 1963, in the Belgian Congo, sisters Hilary Dunbar and Felice Dunbar are torn apart when Felice is sent away on a train with her aunt, who bears a cursed totem talisman shaped like a serpent. As they travel toward Europe, the aunt—driven by the talisman’s pull—attacks Felice, kissing her with blood spilling from her mouth. The train’s conductor discovers the aunt’s deformed corpse, and Felice exits the train with the talisman clutched tightly in her hands, beginning a fate that will shadow her bloodline for years to come.
Twenty-five years later, in Albany, New York, Hilary lives with her architect husband Jack Halloran and their teenage daughter Amy Halloran. Their suburban life is upended when Felice, now a world-traveling model, phones Hilary to arrange a family reunion, only to be met with firm resistance. Hilary refuses to see her sister, and urges her husband to let her run an errand, passing a gun shop along the way. In a shocking moment, Hilary is killed in a gruesome car accident, the incident casting a veil of mystery over Felice’s sudden arrival and Felice’s stated wish to reconnect with the family.
Five months later, Felice returns to Albany and resumes her life as a model for a vitamin company that has relocated from South Africa. The family’s kindly neighbor, Brenda, a nurse, finds Felice unsettling and is wary of her, especially given Felice’s uncanny aura and the allergies Brenda experiences around cats. Felice’s presence stirs tension, especially as Amy and her friend Heather spend time together and head to the local mall. On an escalator, Heather drops her lipstick and temporarily stops to pick it up; her necklace becomes caught in the grate, and Amy tries to help, but Heather is badly mangled—though she survives the accident.
Amy uncovers Felice’s talisman among her belongings, along with a collection of artifacts, including Heather’s bloodstained sunglasses. The revelation heightens Amy’s suspicion, while Felice begins to make romantic advances toward Jack, further straining the already fragile family ties. One night, Jack goes downstairs after hearing a noise and is attacked by a wild cat that escapes through the kitchen window; Amy finds solace in her relationship with Terry, who becomes entangled in the escalating danger surrounding Felice. After confronting Felice at her hotel, Terry is knocked to the side by the cat-like force that stalks Felice, and his death is later staged to look like a suicide.
Desperate for answers, Amy seeks counsel from a local priest, who shares what her mother had told him about Felice and the family’s past. The priest, Father Joe, attempts to intervene, but Felice intervenes with lethal force—causing the priest to be killed by spontaneous combustion inside an elevator. Jack, meanwhile, is summoned back home when Brenda reveals she had a sample of Felice’s blood analyzed and that it resembles the blood of a corpse.
Jack ultimately deserts his plane ride to return home, where he finds Amy near death and Felice looming over him. Felice reveals that Amy is her bloodline and that, in order to survive, Felice must pass the curse to Amy and live on through her blood. Felice seduces Jack, while Amy escapes with Brenda. The two women are forced to confront Felice’s monstrous lineage as they attempt to flee. A wild cat—the terrifying physical manifestation of Felice’s curse—attacks them, but Brenda kills the animal, and Felice closes in on Amy, attempting to kiss her in a bid to transfer the parasite.
A fierce struggle ensues between Jack, Felice, and Amy in the pool. Amy uses electric gardening shears to defend herself, and the struggle continues as Felice’s parasite body begins to wither. The parasitic force escapes the water and makes a last attempt to seize Amy, but an explosion triggered by a propane tank destroys it. In the end, Felice’s body sinks to the bottom of the pool as the family embraces, having survived but forever marked by the curse that has traveled through generations.
