Published in 1915, E. Phillips Oppenheim's The Double Traitor is a gripping espionage thriller set on the eve of the First World War. Francis Norgate, a promising young English diplomat, is cashiered from Berlin after an affair of honor and returns to England, where he stumbles upon a vast German conspiracy—a secret network of spies laying the groundwork for war. Working with British intelligence, Norgate races to expose the plot while navigating shifting loyalties, political intrigue, and a dangerous romance. As the line between patriot and traitor blurs, the novel builds toward a suspenseful climax revealing betrayal on both sides.