A fake fortuneteller, Catherine (who calls herself Caterina), is setting up her shop when an old woman comes in for a reading. She gives the woman a favorable reading and collects her payment, but when she goes to get change the woman substitutes Catherine's deck of cards for one out of her purse.
Later Catherine does a reading for another client, Iris, who has her boyfriend out in the car. Catherine draws the Knight of Swords and asks Iris to cut for another reading. She does but she gets the exact same layout, which predicts that Iris' boyfriend will die. At that moment there's a car crash outside and the boyfriend is killed.
Another man, Isaac comes to get his reading and she deals out the same pattern as before. She hides the Knight of Swords in her blouse as Isaac gets her a glass of water. When he comes back he explains that the Tarot has an ancient power and there's no appeal. He points out that the Knight of Swords is back on the table, much to Catherine's surprise, and he goes off to meet his fate. After he leaves, Catherine throws the cards away and Iris returns, demanding another reading. When Catherine says she's thrown the cards away, Isis points to them on the table.
Catherine lays out almost the exact same reading, a very bad one. She sends Isis away and calls her friend Esther to come over. While she waits, Catherine sets the cards on fire but they don't burn. Esther arrives and tells how Isaac died in an elevator accident. Catherine panics and locks the cards away in a box, and Esther agrees to stay with her. Later, the box bursts open in an explosion of light as Catherine demands to know what they want from her.
Esther helps Catherine piece together when the readings started going bad, and Esther recognizes the older lady as Madame Marlena, a fortuneteller who has been losing business to Catherine. Catherine leaves… as the cards appear in her purse once more.
Catherine arrives as Marlena's apartment and demands a reading. Marlena explains that all Tarot cards come from one, and Catherine mocked them. Marlena warns that they won't leave her, and they can only be removed by passing them on to someone else, just as Marlena (a disbeliever) passed them on to Catherine.
Catherine goes to another psychic, Mrs. McNeill, and asks for a reading. Mrs. McNeill prepares but Catherine interrupts to ask her to let in some light and then switches the cards. Mrs. McNeill deals out the cursed layout with the Knight of Swords as the last card, which flies out of her hand. Panicked, Catherine runs out into the street and burns Mrs. McNeill's date. But a mugger comes up and stabs her, taking her purse. Catherine collapses, dead, with the Knight of Swords lying on the ground in front of her.