The Numbered Murders

A 1939 mystery

In July 1939, three men are shot dead within a few days of each other. The incidents are all in Lancashire but in different police force areas.
When it is eventually realised that the cases are linked, the various constabularies agree to call in the expertise of Scotland Yard. Detective Chief Inspector Adair, who has been holidaying with his wife and daughter in the same county, is tasked with investigating the crimes.
These do not appear to be random shootings. It seems that the gunman has a motive for killing each of the victims. But what could that be? And is the grudge against each one as an independent individual, or are the victims themselves linked in some way?

Satisfying Procedural, Interesting Story

Very good for its clear depiction of the initial mystery and subsequent resolution. No amateurs, no unnecessary drama, no fluff.