The new DI Hardcastle mystery June 1916. Hardcastle is sent to investigate the murder of Colonel Sir Adrian Rivers, Bt. It seems the baronet's second wife, much younger than Rivers, is neither distressed by the murder, nor able to assist in the investigation. It is up to the dogged Hardcastle, aided by DS Charles Marriott, to question an array of characters and narrowly avoid being killed in a Zeppelin raid, before the killer is eventually unmasked...