A powerful period crime novel based on a true story, by the author of Curtain Call and Our Friends in Berlin

The Wallace Murder was a national cause celebre of the 1930s, and is still unsolved over ninety years later. One night in January 1931 William Herbert Wallace, a 52-year-old insurance agent in Liverpool, was handed a phone message at his chess club purporting to come from a 'Mr Qualtrough' who wanted to put some work his way. He had left an address in south Liverpool. The following night Wallace caught a tram from the home he shared with his wife, Julia, in Anfield to visit Qualtrough at 25 Menlove Gardens East - which he had trouble locating. It turned out, after Wallace had consulted passers-by and even a policeman, the road didn't exist. On returning home two hours later he found his wife lying dead in the parlour, her head crushed by violent blows. The elaborate nature of his alibi pointed to Wallace as the culprit. He was arrested and tried, found guilty of murder and sentenced to hang, but the next month the Court of Criminal Appeal overturned the verdict and he walked free.

Ever since, speculation has been obsessive over the killer's identity. The police and the press remained baffled, while novelists, criminologists and eminent lawyers theorised as to who the guilty man might be. Dorothy L. Sayers considered the case in The Anatomy of Murder (1936). James Agate in his diary (1942) called it "the perfect murder", and Raymond Chandler said "The case is unbeatable. It will always be unbeatable"...