December 1917. Ada Hobbes arrives on a frosty morning to clean the house owned by Dr Tindall, a surgeon at the Edmonton Military Hospital. She is shocked to find the blood-covered body of her employer sprawled across the floor. He has been hacked to death.

Detective Inspector Harvey Marmion and Sergeant Joe Keedy arrive to a horrific scene. Someone enjoyed killing him, without a doubt. Their investigation takes them far out of London and on the trail of a very different Dr Tindall, one who was not the respectable local GP everyone thought he was. Marmion and Keedy will need to sift through a number of likely suspects to find the killer behind this gruesome murder.