Philip Davidson (Sir John Mills) is wrongfully jailed for murder, spends twelve years behind bars, and comes out into the world seeking revenge upon the witnesses who lied in presenting the evidence against him at his trial. Among them is Fay Lowther (Elizabeth Sellars), his former fiancee. Shortly after the trial, however, Fay married Detective Inspector Bob Lowther (John McCallum) who worked on the original case. Lowther, anticipating Davidson's intentions, has him constantly watched. But Davidson begins to track down his enemies under the constant surveillance of the police and the newspapers.