Ask a Policeman (novel)

Ask a Policeman is a 1955 detective novel by E.C.R. Lorac, the pen name of the British writer Edith Caroline Rivett. It is the forty first in her long-running series featuring Chief Inspector MacDonald of Scotland Yard. Published by the Collins Crime Club, the title references the popular music hall song Ask a Policeman.

Synopsis
An elderly lady, a leftover from the Edwardian era, reports the disappearance of her nephew, a journalist. What seems at first a routine case quickly becomes a hunt for a murderer when the police investigate his last known address, a large rambling house in St John's Wood. Efforts to discover the truth are further hampered by the death or disappearance of several witnesses.