It's 1950, and Harry Dillon, an Irish, Oxford-educated young detective inspector at Scotland Yard, finds himself drawn into a chilling new case. The investigation begins with the murder of a young woman in Whitechapel, her body left with an unusual clue: a black knight chess piece. Soon after, a second murder occurs, leaving behind another chess piece – a black bishop. As the killings continue, Fleet Street seizes on the macabre story, branding the culprit a 'chess-crazed serial killer' and drawing chilling parallels to Jack the Ripper. Harry Dillon is no stranger to complex cases. With the help of his close friend and future brother-in-law, DI Jim Wilson-Smythe, Harry previously solved the case of the Missing Girl, which began with a murder in a remote Cornish cemetery. Jim is now engaged to Harry's younger sister, Milly, while Harry himself shares a budding romance with Jim's sister, Katherine. Adding to the mix is Sarah, Harry's confidante and neighbour in London, who also played a vital role in his earlier investigation. As the chess-themed killings escalate, Harry faces a web of suspects, red herrings, and cryptic motivations. Determined to uncover the truth, he unravels the bizarre trail of clues in a case that grows increasingly difficult and complex. But can Harry catch the killer before more lives are lost?