The story unfolds in an alternate history setting during World War 1, enriched with steampunk elements and a blend of espionage and supernatural intrigue. Kit Hardwicke, initially introduced as reflecting on wartime experiences, is drawn into a complex web of spy missions against the backdrop of historical events interwoven with fictional deviations. He assumes various identities to infilatrate enemy lines and uncover plots with the aid of a group of friends and colleagues. Central to the plot is Peter Garnett, who is revealed to be a formidable antogonist orchestrating espionage activities for Germany.

Themes of loyalty, sacrifice and duty are explored through Kit's interactions with characters who both aid and obstruct his mission. Ultimately the premise revolves around thwarting Garnett's machinations while grappling with internal conflicts amidst external chaos - a quest for truth beneath layers of lies in a world where history diverges into fantastical realms without losing sight of humanity's core struggles during wartime.