Commander R. F. Heritage, James Mason, is dismissed from the Royal Navy in the Second World War after being found guilty of losing some top secret documents, a blow that sets him on a winding path through a string of encounters and investigations. He moves through Blackpool and beyond, revisiting the places that marked the days just before his downfall, and each stop pulls him deeper into a murky mix of romance, danger, and manipulation.
He begins with Mary, Patricia Medina, a manicurist he first meets at the Hotel Monopole. Mary hints at something important but, enigmatic as ever, she arranges to reconvene at the Bell & Dragon public house outside town. The trail soon grows more perilous when a young Canadian woman, Miss Verity, Joyce Howard, arrives at a remote cottage and discovers Mary dead, gripping a note that reads “Child’s Theatrical Agency.” Miss Verity barricades the door as Heritage arrives and she has clearly seen his face. She then heads to Blackpool to report the murder, and Heritage follows, only to find that the body has vanished. The police threaten to charge Miss Verity with filing a false report, turning the situation into a tense stand‑off.
Their courses then lead toward London, as they track the clues to Child’s Theatrical Agency and, from there, to the BBC. Heritage brings a different woman to an audition—the plan is murky, and the mysterious Canadian woman who shadowed him continues to trail him as well. On a northbound train to Liverpool, where Child runs a dance academy, Miss Verity finds herself under the gaze of enemy agents. An undercover attempt to have her shot in the dark through a tunnel is foiled when she manages to seize Miss Verity’s handbag, and Heritage nonetheless intervenes to rescue her at the station barrier, keeping her safe for the moment.
In Liverpool, Child and his hypnotist, the Great Riccardo, join the intrigue and hypnotize a Royal Navy officer, Petty Officer Grant, into revealing secrets about HMS Dandelion, commanded by Lippinscott. The pair aim to hypnotize Miss Verity to uncover what she knows, compounding the danger surrounding Heritage and those around him. The tension spills into a bar, where Heritage’s former batman Mansel, Edward Rigby, staggers into a brawl to create a diversion, and Heritage uses the distraction to rescue Miss Verity once more.
Meanwhile, in that same place, Carter, Ronald Ward, arranges for a woman named Bobby, Peggy Dexter, to strike up conversation with Commander Lippinscott, David Farrar. At the same time, the harmonica player—Max, Ronald Chesney—discreetly communicates a coded message through his music. The web tightens as Lippinscott and Heritage appear to be playing a shared game, each a pawn in a larger plan designed to trap the traitors.
Morning reveals further twists: Bobby departs with Lippinscott, leaving the others to proceed with their hotel plans. Miss Verity tails one of the spies to the countryside by hiding in the back of his car, while Mansel and the police keep her in sight. In the garden, Riccardo is scheming to dispose of the manicurist’s body by burning and burying it in a scarecrow—an eerie scene that compounds the film’s mood of paranoia and concealment.
Back at the hotel, the disguise experts decode the musical notation played by the harmonica player, exposing the sinister scheme for what it is. Carter and Dr Benson, Eric Mason, step onto the stage for a magic act, and the moment becomes a crucial turning point as they attempt to seize the coded message from Lippinscott during the performance. Yet the message tucked in his pocket proves to be blank, and the room’s tension peaks as Heritage, stepping into the spotlight as a willing participant, reveals the scam to the assembled watchers.
With the police surrounding the room, Heritage confronts the plot in a climactic display of wit and nerve. He exposes the conspiracy not with brute force, but by turning the room into a vantage point for the authorities to close in. The moment culminates with a kiss shared between Heritage and Miss Verity, a quiet counterpoint to the day’s feverish intrigue, leaving her to weigh what she has learned and what she must now face.
Throughout the espionage, the story threads together themes of loyalty, identity, and the precarious line between performance and reality. The tale moves from seaside towns to theatres, from coded messages hidden in music to hypnotic interference, weaving a tapestry where every character might be bluffing or telling the truth. In the end, Heritage’s calm resolve and the unexpected alliance with Miss Verity push back the shadows, offering a cautious note of closure in a world where trust has always been in short supply.
