In February 1915, the Great War is still raging on the Western Front, but in Westminster, at the centre of Hardcastle's bailiwick, a policeman is shot dead. At first, Hardcastle believes the murderer to have been a disturbed burglar.
But as enquiries continue, attention focuses on an antiquarian bookseller, a struggling artist, a reporter, officers of the Royal Flying Corps, both in England and in France, and the activities of Isabel Plowman, the wife of one of them and the lover of others.
