Clem Morgan, Trevor Howard, a demobilised Royal Air Force veteran struggling to find steady work after the war, slides into a murky world of black‑market parcels moved in coffins to Narcy’s headquarters, tucked away inside a funeral parlour. He justifies it as tolerable necessity until a coffin turns up with drugs hidden inside, shattering his uneasy routine. He confides in his girlfriend, Ellie, that tonight’s warehouse loot will be his last job, but the night spirals beyond control as Narcy Griffith Jones betrays him, triggering the alarm while Clem is still inside.
Inside the chaos, Clem narrowly reclaims a seat in the car, now accompanied by Narcy and Soapy, Jack McNaughton, as they pull away from the scene. Narcy orders Soapy to ram a police officer, and in a desperate bid to save the man’s life, Clem wrestles with the wheel, crashing the car into a lamppost. Narcy knocks him unconscious and the gang rifles through the wreck while the police swarm in. Inspector Rockliffe, Ballard Berkeley, arrives with other officers to find the officer dead and Clem badly injured, the obvious scapegoat in a case that will shape his fate.
Convicted of manslaughter, Clem is sentenced to fifteen years in HM Prison Dartmoor. In prison, his world widens beyond the concrete walls as Sally Connor, Sally Gray, visits to share the grim rumor that Narcy is now with Ellie and that Clem is being framed. Sally offers to push Soapy toward giving evidence, but Clem insists she stay away. Meanwhile, back in London, Sally reveals to Cora, Rene Ray, that she has seen Clem and urges Soapy to talk, only to be brutally beaten by Narcy when Narcy discovers the visit.
Clem makes a dramatic escape from prison and seeks a safe refuge at a remote farmhouse, where Mrs Fenshaw, Vida Hope, offers him food, warmth, and a chance to vanish for a while. She discreetly urges him to finish a rival, her husband Mr Fenshaw, Maurice Denham, who lies drunk and oblivious most of the time. Mrs Fenshaw presses Clem to shoot him, arguing it would be a mercy, but Clem refuses and leaves, though his gun-handprint fingerprints linger on the weapon. Mrs Fenshaw then uses the gun to kill Mr Fenshaw, turning Clem into a suspect for another murder.
Furious and wanted, Clem slips back to London and finds Sally again, only to discover Narcy’s gang has abducted her and Cora is already being held. Narcy forces Cora to reveal Soapy’s hideout, and Jim, Michael Brennan, is sent to finish Soapy off at a rundown hotel. Clem, still on the run, works to locate Cora and Soapy while Inspector Rockliffe remains skeptical of Mrs Fenshaw’s tale but wary enough to keep Clem as a possible suspect rather than a confirmed killer.
Clem is captured again, but Rockliffe lets him go, using him as bait to draw Narcy’s gang out of hiding at the Valhalla funeral parlour. A brutal rooftop clash between Clem and Narcy ensues, culminating in Narcy’s fall. With Narcy dying, Rockliffe, Sally, and Clem press him for the truth about who killed the policeman, but Narcy clings to his story and dies with it unresolved. As Jim, Bert, and Clem are escorted into police cars, the weight of possible innocence and guilt looms large.
“It's all right Miss Connor. We'll get all the facts before we're through,” Rockliffe promises, as he radios for more inquiries and hints that fresh evidence could still reach the Home Secretary if circumstances allow. In the fading tension, Bert mutters from the crowd, and the film lingers on the idea that justice may hinge on new revelations rather than the certainty of the moment. Fat chance they’d believe me.
