Some time after the tragic drowning of their young daughter, Christine, in an unfortunate accident at their idyllic English countryside home, John Baxter and his emotionally devastated wife, Laura, decide to travel to Venice. John has been commissioned by a bishop to restore an ancient church, eager to escape the haunting memories of their loss. While dining at a restaurant, Laura encounters two elderly sisters, Heather and Wendy. During this seemingly ordinary meal, Heather, a blind woman who claims to possess psychic abilities, disconcertingly reveals to Laura that she is able to "see" the spirit of their deceased daughter. This shocking revelation leaves Laura shaken, and she soon faints at the table.
Laura's fainting spell lands her in the hospital, where she recounts Heather's message to John. Initially skeptical, John finds himself unexpectedly pleased by the uplifting change in Laura's demeanor. That evening, after returning home from the hospital, an intimate moment unfolds between John and Laura, igniting their passion once more. However, as they set off for dinner, they lose their way and briefly become separated. In this disorienting moment, John catches a fleeting glimpse of a small figure clad in a red coat—the same vibrant coat Christine wore on the tragic day she passed.
The following day, Laura seeks the company of Heather and Wendy for a séance aimed at contacting Christine's spirit. Upon returning to their hotel, Laura informs John that Christine has warned them about a looming danger he faces, insisting they must leave Venice immediately. Although John argues against Laura's concerns, their evening takes an ominous turn when they receive a phone call notifying them that their son has endured an accident at boarding school. This crisis forces Laura to leave for England, while John commits to completing the church restoration project. Shortly thereafter, John finds himself nearly killed when scaffolding collapses beneath him, making him believe that this incident is the very "danger" the sisters had foreseen.
That day, assuming Laura is back in England, John is taken aback when he spots her on a vessel participating in a funeral procession, accompanied by Heather and Wendy. Fearing for his wife's mental stability, especially given unsettling reports of a serial killer on the loose in Venice, John rushes to report her sudden disappearance to the authorities. The inspector assigned to the murder cases is strangely suspicious of John and has him followed. As John ventures on a desperate search for Laura and the sisters—where he once again glimpses the eerie figure in the red coat—he takes a moment to contact his son's school, only to realize that Laura is indeed in England.
After confirming Laura’s whereabouts, a bewildered John makes his way back to the police station to inform them about his findings. Meanwhile, Heather has been brought in for questioning, and feeling remorseful, John decides to escort her back to their hotel. Shortly after their return, Heather enters a trance state. A sense of foreboding fills the air, urging her to alert Wendy to pursue John, sensing that nestled within this dismissal lies a looming tragedy. But alas, Wendy cannot catch up with him.
While wandering the streets, John catches yet another glimpse of the mysterious figure clad in red and, driven by an instinctive need to discover the truth, he pursues it. Cornering this entity in a desolate palazzo, he approaches, believing it to be a child in need of help only to have the figure turn towards him, revealing a grotesquely disfigured female dwarf. Stunned into immobility, John does not defend himself as the dwarf brandishes a meat cleaver, delivering a devastating blow that slices his throat. In his final moments, John comprehends—far too late—that the spectral visions he encountered were harbingers of his own demise and impending funeral.
