 Novelist-turned-soldier Edgar Brodie is recruited by British intelligence during World War I to ferret out a mysterious German spy and eliminate him. Brodie is given a new identity by his "handler," R, and teamed with two professional agents, an amoral, but amusingly deadly assassin known as The General and Elsa Carrington, a beautiful blonde who will pose as his wife and cover for his new identity. After they mistakenly target an innocent old man as the operative and The General cold-bloodily murders him, both Edgar and Elsa question the morality of the mission, especially when The General only finds amusement in the blunder. When they eventually discover the spy s true identity, Elsa is determined to stop her two fellow agents from fulfilling the mission.