Hardcastle's Armistice

On Armistice Day 1918 DI Ernest Hardcastle of the Whitehall Division of the Metropolitan Police finds himself in familiar territory when he investigates the murder of a prostitute whose body is found beneath Brighton's Palace Pier. Is it a casual robbery or are there more sinister motives for her death?

A beach photographer and an army officer involved in the 1917 mining of the Messines Ridge both feature high on Hardcastle's list of suspects. And, in a parallel enquiry, a Westminster alderman makes an allegation of blackmail. Is there a connection?