Eve Gill, portrayed by Jane Wyman, is a passionate aspiring actress attending The Royal Academy of Dramatic Arts. During a rehearsal, her world is turned upside down when she is unexpectedly visited by her friend, the troubled actor, Richard Todd, who is in a state of panic. He reveals that he is entangled with the flamboyant stage actress and singer, Marlene Dietrich, who has just become embroiled in a chilling murder case. According to Jonathan, Charlotte has committed an unspeakable act—killing her husband during a heated argument.

Dressed in a bloodstained gown and desperate for help, she lured Jonathan to her home under false pretenses, and he unwittingly found himself in the midst of a grisly crime scene where Mr. Inwood was deceased. He tells Eve that rather than turn Charlotte over to the authorities, he attempted to conceal the horrific event by staging a burglary gone wrong. However, in his panic, he was spotted by Charlotte’s maid, Kay Walsh, leaving him a wanted man with the police hot on his trail.

Eve’s affection for Jonathan compels her to provide sanctuary, whisking him away to a coastal hideout linked to her father, Alastair Sim. Though the Commodore initially harbors doubts about Jonathan’s culpability—especially after detecting that the blood on Charlotte’s dress appears to be smeared intentionally—he finds himself embroiled in a web of deception and intrigue. Despite the chaos, he ultimately destroys the dress in a fit of rage.

Determined to uncover the truth and save Jonathan, Eve takes matters into her own hands. She deceives Nellie Goode into feigning illness, allowing Eve to adopt the disguise of a Cockney maid named “Doris Tinsdale” and infiltrate Charlotte’s household. During her undercover mission, she crosses paths with the handsome Detective Inspector Michael Wilding, who finds himself drawn to Eve. The tension escalates as Eve navigates her charade as a maid while attempting to extract information from the inspector about his investigation.

As the story unfolds, Eve invites Inspector Smith to tea at her home, where her father inadvertently hints that Jonathan has vacated their coastal haven. Meanwhile, Charlotte returns to the stage, her musical performance overshadowed by her tumultuous personal life. She is secretly sought out by Jonathan, who implores her to escape with him. Yet, Charlotte is reluctant to abandon her career for a fugitive, all while carrying on a hidden affair with her manager, Hector MacGregor.

Eve, still disguised as Doris, continues her mission to aid Jonathan, who ultimately hides in her family’s London home. Although he expresses gratitude for her support, Eve’s affections begin to shift towards Inspector Smith, complicating her loyalties even further. When the truth of her masquerade is revealed by Nellie, Eve resorts to bribery to ensure her cover remains intact.

The complexity heightens when the Commodore orchestrates a scene during a charity garden party featuring Charlotte; he enlists the help of a child with a doll dressed in a bloodstained gown to unsettle her. This act backfires, leading to Inspector Smith’s growing suspicion of Eve’s true identity.

In a climactic confrontation, both Eve and Smith unite in a ruse intended to draw a confession out of Charlotte, with microphones set to capture the evidence. As Charlotte admits her involvement in the crime, tension mounts when Jonathan’s presence is uncovered, and chaos ensues as Eve erupts in hysteria, which creates a window for Jonathan to flee.

However, in a shocking turn of events, Jonathan confesses to Eve that he indeed killed Mr. Inwood, manipulated by Charlotte to pave the way for her affair with Freddie. Realizing that she has been living a lie, Eve struggles to persuade Jonathan to surrender as his unstable mind spirals out of control. In a desperate bid, she aids him in his escape, only to lock him away from the police to prevent any further carnage.

The dramatic conclusion unfolds as Jonathan becomes ensnared in the collapsing safety curtain of the stage, leading to an intense final act that reverberates with tragedy. The story culminates with Eve and Inspector Smith exiting the theatre, grappling with the haunting aftermath of their harrowing experience.