A supernatural thriller about a novelist, who possesses the mental power to control life and death. John Morlar (Richard Burton), a well-known novelist, is savagely attacked in his London flat. Barely alive, he is taken to hospital. Detective Brunel (Lino Ventura) is assigned to the case. He comes across Morlar's journal, which leads him to a mysterious woman named Zonfeld (Lee Remick) who is Morlar's doctor. Zonfeld discloses that her patient is obsessed. He feels he bears an awesome telekinetic power - the power to 'will' destruction and death. He can make airplanes crash, buildings crumble, start raging fires and unleash mighty floods. He believes he possesses the gift of evil, and dangerously demonstrates his power. What at first seems preposterous, soon becomes sickeningly real. Morlar is able to wreak havoc at will. Brunel desperately wants to stop the next tragedy, but can he kill this man? If released from his mortal confines, how far can the power of his mind roam? An effective fast paced thriller, which ends in a spectacular and spine-chilling climax.