Newspapers cover the shocking 1948 murder of Margaret Strauss, who was tragically stabbed during a robbery, and the key piece of evidence—her missing anklet. Her husband, Roman Strauss, a talented composer, finds himself wrongfully convicted and is sentenced to death. Just before his execution, he has a fateful meeting with reporter Gray Baker. When asked about Margaret's murder, Roman seems to whisper something to Baker, but the journalist chooses to keep this revelation a secret, leaving many questions unanswered.
Fast forward forty-three years, and we meet Mike Church, a private detective on a quest to uncover the identity of a mysterious woman who appeared at his childhood orphanage. Plagued by amnesia and haunting nightmares, she is taken in by Mike, who enlists the help of his friend Pete Dugan to circulate her photograph in hopes of finding her family. Enter the antiques dealer and hypnotist Franklyn Madson, who suggests that hypnosis might be the key to unlocking her lost memories.
Initially, their attempt at hypnosis is futile, but Madson proposes an unorthodox method of past life regression. Although skeptical, Mike is stunned when the woman begins recounting the lives of Margaret and Roman, detailing their journey from courtship to wedding, as if she were narrating a story. After the session, she can finally speak, but her memories remain clouded. Madson provides them with old Life magazine articles that feature the tragic murder, revealing that the woman and Mike bear a striking resemblance to the ill-fated couple.
Determined to help, Mike visits Cozy Carlisle, an old psychiatrist, who insists on continuing sessions with Madson, claiming that exploring the tumultuous dynamics between Margaret and Roman could be the key to resolving the woman’s amnesia. As Mike affectionately nicknames her "Grace," he finds himself falling for her, yet complications arise when a man named Doug comes forward, claiming that she is his fiancée, Katherine. Mike quickly discovers Doug's deceit and confronts him, driving him away.
Through hypnotic sessions, Grace begins to remember snippets of Roman's life, including his struggles with writer's block and financial troubles, coupled with suspicions about Margaret's loyalty. As tensions escalate, a critical moment occurs when Grace imagines Mike standing over Margaret with scissors, convinced he harbors malicious intentions. Mike fervently tries to reassure her, but in a moment of vulnerability, he mistakenly calls her "Margaret," leading him to seek regression himself.
In a twist of fate, under hypnosis, Mike realizes that he has been embodying Margaret and that Grace is, in fact, Roman. This profound understanding remains unspoken, as he grapples with the implications of what he has uncovered. Meanwhile, Pete Dugan discovers that Grace is actually artist Amanda Sharp, who suffered memory loss after being confronted during a mugging incident. In a desperate attempt to protect herself, she receives a gun from Madson, who stirs her fears about Mike.
A pivotal encounter occurs when Mike seeks out Gray Baker, now residing in a nursing home, to unravel Roman's buried secrets. Baker maintains that Roman never confessed to guilt but rather shared a tender kiss before his execution. He urges Mike to track down Inga, a source who might reveal the true events leading up to the murder.
The narrative takes a darker turn when Mike confronts Madson in his shop, ultimately tracking down Inga. She reveals the horrifying events of that fateful day in 1948. Inga had foolishly declared her love to Roman, only to face rejection. It was Frankie, her son, under the false belief that Margaret caused his mother's despair, who committed the murder. Roman was left to bear the blame, found in the gruesome aftermath with the murder weapon in hand.
Haunted by the past, Madson (revealed to be Frankie) plots to eliminate Amanda, believing her spirit embodies vengeance. Inga's remorse leads her to hand the anklet to Mike before tragedy strikes. As Amanda grapples with the truth, a series of violent confrontations ensue, culminating in attempted murder and self-defense that challenges the very fabric of their identities.
In a dramatic finale, Mike manages to expose Madson's true nature during a chaotic struggle, leading to a gripping resolution marked by betrayal, survival, and a final twist of fate where Amanda, against all odds, emerges from the shadows of the past. The narrative concludes with a poignant montage of Mike and Amanda's budding romance, intertwined seamlessly with glimpses of the once-joyous moments in Margaret and Roman’s life, alluding to the timeless nature of love amidst tragedy.
