July, 1917. DI Ernest Hardcastle and his assistant, DS Charles Marriott, investigate the murder of a cashier operating in London's Victoria Station. An army officer claims to have seen the murderer running away, and an army cap left behind appears to identify the criminal. Hardcastle believes that it will be a simple matter to go to Aldershot and arrest him, but things are never as easy as they seem. Soon Hardcastle and Marriott find themselves investigating...

During the last days of World War I, Det. Inspector Ernest Hardcastle is encumbered with a complicated murder investigation.
 
March, 1918. The Great War is grinding slowly to its bloody finale. Divisional Det. Inspector Ernest Hardcastle, head of the Whitehall Division of the Metropolitan Police, is called to a body recovered from the Thames. Mavis Parker, the victim’s attractive widow, proves to be a good-time girl,...

June 1918. A patrolling constable discovers the body of Georgina Cheney, wife of a naval commander, in the basement area of a house in Westminster. At first it is thought to be suicide or even a tragic accident. But as Divisional Detective Inspector Ernest Hardcastle of the A or Whitehall Division of the Metropolitan Police begins to investigate - ably assisted by Detective Sergeant Charles Marriott - they soon discover a different story. It is clear...

March, 1919. The commissioner of police at New Scotland Yard has a task for Divisional Detective Inspector Hardcastle of A Division: find Lily Musgrave, the missing daughter of Ausen Musgrave MP. Hardcastle, aided by Detective Sergeant Charles Marriott, discovers that the headstrong Lily provides risque entertainment for a number of ex-officers. When she return home of her own accord, however, Hardcastle assumes the case is closed and turns his attention...

Detective Inspector Walter Hardcastle is following in his father's footsteps, but is his rapid rise about to be threatened by a spate of disturbing break-ins linked to the war effort August, 1939. As war looms, Detective Inspector Walter Hardcastle is following in the footsteps of his father, Ernest, and progressing through the ranks of the Metropolitan Police. Summoned to the office of Charles Marriot, Deputy Assistant Commissioner of CID at New...