The Spies of Hartlake Hall

London, 1917. When a man’s body is found deep inside Room 40, a highly secretive organization within the Admiralty, intelligence agent Patrick Gallagher is brought in to investigate.

The man has no identification and was discovered in a room locked from the inside with no other apparent exit. Moreover, found in his pocket is a highly confidential telegram which would be political dynamite if it were to fall into the wrong hands. Few know about the death and, to avoid raising further suspicion, Gallagher invites those involved to his family’s home at Hartlake Hall for questioning.

But they are not the only guests at the stately hall; members of a shooting party are also staying for the weekend. Over the course of three days, further bodies pile up as a ruthless killer continues to pull the strings from the shadows. As WWI rages on in Europe, many of the guests have secrets to hide, and Gallagher must move quickly in order to expose a deadly spy among them.