The Turkish Gambit by Boris Akunin

Set against the backdrop of the Russo-Turkish War of 1877-1878, this historical detective novel follows the cunning and resourceful Erast Fandorin as he navigates a web of espionage, deceit, and political intrigue. Tasked with uncovering a traitor within the Russian military ranks, Fandorin must employ his sharp wit and keen observation skills to unravel a complex conspiracy that threatens to tip the balance of power in the conflict. As he delves deeper into the mystery, he encounters a cast of vivid characters, each with their own secrets and motives, leading to a thrilling and unexpected climax.