As Monsieur Brunel (Harry Andrews), a keen French detective participating in an exchange program in London, examines the seemingly ordinary case of novelist John Morlar (Richard Burton) who appears to have been murdered, he begins to unveil a series of cryptic clues and distressing truths that upend his grasp of reality. The investigation takes a startling twist when Brunel discovers that the victim, against all odds, is not dead but alive, despite suffering significant head injuries. Promptly, Brunel rushes him to the hospital for urgent care.
Delving into Morlar's journals and engaging with Dr. Zonfeld (Michael Hordern), a psychiatrist with whom Morlar had been probing the enigmas of the human mind, Brunel reconstructs the novelist's life story, revealing a haunting narrative marked by inexplicable tragedies and sudden losses. Through a series of flashbacks, it becomes evident that Morlar lived under the shadow of an ominous sense of precognition, convincing himself that he could psychically attract catastrophic events to fruition.
The investigation further unravels Morlar’s escalating obsession with this belief, a conviction that deepened after an unsettling forecast by a supposed psychic who evaluated his hands. Initially dismissive, Dr. Zonfeld is left astounded when Morlar unintentionally causes a jumbo airliner to plummet into a London skyscraper, resulting in the death of all passengers onboard shortly after their session.
As Brunel pulls at the tangled threads of Morlar's existence, it surfaces that the novelist's disturbing past and mounting fears of the world led him into a spiral of paranoia and self-doubt. The investigation raises profound questions, leaving Brunel to contemplate the blurry distinction between reality and Morlar's distorted worldview.
In a gripping turn of events, Brunel realizes the depth of the conspiracy as he discovers that Zonfeld attempted to silence Morlar, resorting to violence in a desperate attempt to avert further disastrous occurrences. The latest catastrophe, which unfolded on a global broadcast, involved American astronauts on a daring lunar mission, leaving Brunel crushed under the weight of this revelation. Upon confronting Zonfeld, she eventually admitted to her vile act of attacking Morlar with a blunt weapon and leaving him mortally wounded. However, Brunel hesitates to take her into custody, his growing apprehension about Morlar's potential telekinetic powers holding him back.
After this harrowing revelation, Brunel returns to Zonfeld's clinic only to find that she has tragically taken her own life, leaving behind a sorrowful note apologizing for the chaos she had caused. Meanwhile, Morlar, recuperating in his hospital bed, continues to unleash havoc, resulting in the collapse of a historic cathedral during a high-profile charity event. This act of destruction was specifically aimed at the “unworthy” individuals who gathered to support its restoration. Driven by a sense of urgency, Brunel hurries to the scene, determined to halt the chaos, yet Morlar's seemingly superhuman abilities prove to be a formidable barrier.
As Brunel grapples with the reality of Morlar's powers, he notices Morlar ominously jotting down a note indicating his next target: the Windscale nuclear power station. The chilling prospect sends a wave of dread through Brunel, as he comprehends that this could be Morlar's most catastrophic act yet, with disastrous implications that might plunge the world into unchecked chaos and devastation.
