The Dead of Winter — David Stuart Davies

Introducing Rupert Wilde, the smart and sophisticated new sleuth in the first of his Golden Age mysteries. 

Having survived the First World War and been decorated for his efforts, Rupert Wilde is now back in civvy street wondering what to do with his life. On a whim he accepts his Aunt Julia's invitation to a Christmas house party at Pelham House in the wilds of rural Norfolk. He takes with him his newly appointed assistant Kishen, a young Oxford educated Indian whom he met when he rescued him from a violent mugging. Little did Wilde know that there would be murder, intrigue and mutilated bodies awaiting him behind the ancient walls of Pelham House. Wilde and Kishen turn detective to get to the bottom of these puzzling and ghastly festive felonies.