Ewen is a British barrister and naval intelligence officer who runs Section 17M. A King's Counsel from a wealthy Jewish banking family, he possesses a sharp legal mind capable of anticipating enemy logic. He throws himself entirely into his work, sometimes blurring the lines between his own life and the fictional persona he constructs for the operation.

Charles is a flight lieutenant in the Royal Air Force seconded to MI5. Hindered by poor eyesight that keeps him from flying, he possesses an eccentric imagination highly suited for deception warfare. He is the conceptual originator of the plot, bringing a bizarre but effective creativity to the British war effort.

Glyndwr is a 34-year-old Welshman who lived a life of extreme poverty and hardship before his death. Because he has no known relatives to claim him and his body shows signs consistent with exposure, British intelligence requisitions his remains without familial consent. He is posthumously transformed into the fictional Major William Martin to carry out the intelligence ruse.

Karl-Erich is an ambitious German intelligence officer stationed in Spain. Despite his aristocratic background and fastidious appearance, he is highly vulnerable due to his Jewish ancestry, which drives his desperate need for career-saving successes. He is a prime target for British misinformation because he tends to believe what he wants to be true.

Alan is a British naval attaché and a former novelist with a history of adventuring in South America. He operates in nominally neutral Spain where he uses his deep understanding of Spanish politics and German espionage to manage the reception of the false documents. He acts as the on-the-ground stage manager for the deception's overseas phase.

Norman is the seasoned commander of the submarine HMS Seraph. Having previously transported high-ranking officials on secret missions, he brings practical military competence to the theoretical deception plan. He is tasked with the delicate final delivery of the corpse into Spanish coastal waters.

Adolf is an aggressive and effective Abwehr agent stationed in southern Spain. The son of a wealthy industrialist, he maintains tight surveillance on Allied shipping and holds significant influence over local Spanish officials. The British specifically target his territory, knowing his diligence will ensure the documents move up the German chain of command.

Jean is a bright and attractive young secretary in the intelligence service. She agrees to provide a photograph of herself in a swimsuit to serve as the visual representation of Pam, the fictional fiancée created for the deception. Her involvement pulls her into a strange, role-playing dynamic with the operation's chief architect.

Alexis is a meticulous former banker and Hitler’s most trusted intelligence analyst. He holds the ultimate authority for validating enemy intelligence. Despite his sterling reputation within the German high command, he harbors deep private misgivings about the regime he serves.

Sir Bernard is a prominent Home Office pathologist whose expert medical opinion lends authority to the operation. He advises the planners on how to select a corpse that can fool foreign medical examiners, displaying absolute confidence in his assessments.

Sir Bentley is the coroner for St. Pancras in London. Eager to contribute to the war effort, he uses his legal authority and access to mortuaries to secretly bypass normal civilian procedures, securing and storing the remains needed for the plot.

Ian is a creative assistant to the director of naval intelligence. Drawing inspiration from detective fiction, he authors the Trout Memo, which contains the initial seed of the idea that eventually evolves into the corpse-dropping operation.

John is the director of British naval intelligence. He understands the psychological aspects of warfare and the need for unusual thinkers in espionage, actively recruiting men whose minds work differently than traditional military officers.

Francis is an older British official living in Spain who secretly runs an underground network aiding the Allies. He is tasked with orchestrating a public performance of anxiety over the missing documents, ensuring the Spanish and Germans take the bait without recovering the briefcase too quickly.

Ivor is a passionate communist and organizer of international table tennis. His political sympathies draw intense scrutiny from British counterespionage officers, creating a layer of security risk and familial tension for his brother in Naval Intelligence.

Iris is Ewen's wife, living abroad to ensure the safety of their family. She works for British Security Co-ordination in New York, maintaining a transatlantic correspondence with her husband as he becomes increasingly absorbed in his clandestine work.

Juan, codenamed Garbo, is a highly effective double agent working for the British. He feeds absurd, manufactured reports to the Abwehr, serving as a primary case study for how easily German intelligence officers accept information that validates their preconceptions.

John is an Oxford academic and mystery writer who oversees double-agent operations for British intelligence. He approves the initial concept for the corpse deception and contributes specific details to the fictional officer's constructed identity.

Wilhelm is the Abwehr chief at the German embassy in Spain. Though officially in charge, he finds himself increasingly sidelined by his ambitious subordinates, though he retains the authority to fast-track crucial intelligence to Berlin.

José is a local Spanish fisherman operating near Huelva. He discovers the corpse floating in the water and hauls it ashore, setting the physical events of the deception into motion on the Spanish mainland.

John oversees the broader strategic illusions designed to mask the Sicily invasion. He clashes occasionally with the naval intelligence team over the specifics of their forged documents, demanding absolute perfection in the drafted letters.