On a stormy night at a secluded retreat along the English coast, Christine Clay, [Pamela Carme], a successful actress, argues passionately with her jealous ex-husband Guy, [George Curzon], who refuses to accept their Reno divorce as valid and loudly accuses her of having an affair. The tension peaks when she slaps him and he storms out, his eyes twitching in a telling, electric tremor that hints at deeper unease.
The next morning, writer Robert Tisdall, [Derrick De Marney], is strolling by the shore when Christine’s body washes up. He recognizes her and races for help, but two passing young women witness him fleeing the scene with the corpse, setting the stage for a high-stakes mystery. The police quickly fix their suspicion on Tisdall, painting a picture of possible romantic entanglement and a motive tied to money—Christine had left him a substantial sum in her will—and he faints at the shocking news.
Erica Burgoyne, [Nova Pilbeam], daughter of Col. Burgoyne, [Percy Marmont], the local police chief, helps revive Tisdall and steps forward to assist in proving his innocence. Scotland Yard detectives grill him through the night, and the case grows more tangled as they insinuate an affair. Despite the intense pressure, Erica’s involvement deepens as she becomes convinced of Tisdall’s innocence and chooses to aid him rather than watch him fall.
Tisdall is arraigned but saddled with an incompetent solicitor, and the crowded courthouse offers him a risky escape opportunity. He slips away, clinging to a chance for freedom by riding on the running board of Erica’s Morris car. When the vehicle runs dry of petrol, he admits himself to Erica and she, though wary, begins to trust him enough to keep him close as they go on the run together.
As they flee, they realize they must stay one step ahead of the pursuing detectives. Erica, increasingly convinced of Tisdall’s innocence, becomes a steadfast ally, while he does his best to clear his name by following a crucial clue—the fate of Christine’s coat. If the belt from Christine’s raincoat is still missing from the coat found beside the body, it can’t be Tisdall’s, a detail they race to verify.
Their search leads them to Old Will, [Edward Rigby], a homeless china-mender who is somehow tied to the coat. Will isn’t the thief; he explains that a man with twitchy eyes had passed the coat to him, and the belt was already gone. This clue deepens the mystery and pushes them toward a hotel connection that might tie the whole crime together.
After a period of separation, Erica is taken in by the police, and her father’s position becomes a sore point—he ultimately resigns rather than arrest his own daughter for aiding a felon. Tisdall, desperate to bring the real culprit to light, sneaks back into the house to confront them, hoping to surrender and claim he merely abducted Erica to protect her. Erica reveals another hint: a pocket-turn of matches from the Grand Hotel, suggesting a link to Christine’s murder that neither had anticipated.
The trail moves to the Grand Hotel, where Erica and Will search for additional evidence. It is there that the truth about Christine’s killer begins to surface: Guy, the ex-husband, is revealed as the drummer in the hotel’s ballroom, performing in blackface, with his eyes twitching as a telltale tic in moments of stress. The sight of Old Will in the audience, plus the presence of nearby police who have shadowed Will hoping he would lead them to Tisdall, throws Guy off his game. He performs poorly, the conductor’s criticism intensifying his anxiety, and during a break he takes medicine to steady the tic, only to become drowsy. In the moment of truth, Guy is confronted, and he confesses his crime, finishing with a hysterical laugh as the mystery collapses into revelation.
