The Games Keeper. The Slim Hardy Mystery Series, #3

Having fallen on hard times, disgraced soldier turned private investigator John "Slim" Hardy is hired by rich and enigmatic land owner Oliver Ozgood to uncover the identity of a mysterious blackmailer. The man is demanding a fortune in exchange for his silence. He claims to be Dennis Sharp, a former employee of Ozgood, and threatens to reveal secrets that will soil Ozgood's family name and send the patriarch to prison.
There's only one problem. Dennis Sharp is dead, killed by Ozgood himself. In search of answers, Slim moves to the remote rural hamlet of Scuttleworth in the Devonshire countryside, where he will confront demons both from within and without in his most challenging case yet. The Games Keeper is the third book in the Slim Hardy Mystery series. While the stories follow a rough sequence, they can be read in any order.
Other titles available:The Man by the SeaThe Clockmaker's Secret