The Unlikely Spy

Set during World War II, the novel weaves together the stories of a German spy operating deep within British society, the intelligence officers trying to stop her, and the deception operations both sides wage before the D-Day invasion of Normandy.

In November 1938, a German agent murders Beatrice Pymm, a solitary English painter, in Suffolk. The killer stabs Pymm with a stiletto, drives the body across the country, and buries it in a shallow grave after crushing the victim's face to prevent identification. Near the grave, she plants forged Dutch identity papers so that police will identify the body as a dead Dutch tourist. The spy had entered Britain legally under this Dutch identity; by killing Pymm and staging her drowning, she ensures that when MI5 (Britain's domestic counterintelligence service) uses passport records to hunt foreign agents, the Dutch woman will appear to be dead, and no one will search for the spy. She is Anna von Steiner, the daughter of a Prussian diplomat and an English mother, coerced into espionage by the Abwehr (German military intelligence) through threats against her father. In England, she becomes Catherine Blake, a war widow volunteering as a nurse in Earl's Court, London.

A parallel storyline introduces Peter Jordan, a brilliant American chief engineer at the Northeast Bridge Company. In the summer of 1939, his wife Margaret, daughter of the wealthy banker Bratton Lauterbach, is killed in an automobile accident on Long Island. Years later, Jordan is sent to London to work on Operation Mulberry, a top-secret project to construct artificial harbors and tow them across the English Channel on D-Day. The project's centerpiece is the Phoenix caissons, giant concrete and steel units designed to create breakwaters off the Normandy coast. If Germany discovers their purpose, it could deduce that the invasion will target Normandy rather than the heavily fortified Pas de Calais.

In May 1940, Winston Churchill recruits Alfred Vicary, a bookish history professor at University College London, into MI5, Britain's domestic counterintelligence service. Vicary is a small, limping man with a brilliant mind for deception and a personal life defined by solitude since Helen, the woman he loved, ended their relationship decades earlier. His superior, Brigadier Sir Basil Boothby, is a career intelligence officer who resents Vicary as an outsider imposed by Churchill.

In January 1944, at Hitler's Wolf's Lair, Admiral Wilhelm Canaris, the head of the Abwehr and a secret leader of the anti-Hitler resistance, is ordered to determine the time and place of the Allied invasion. Canaris passes the assignment to Kurt Vogel, a former lawyer who runs a secretive network of sleeper agents called the V-Chain. Vogel receives intelligence about Jordan's presence in London and activates Catherine Blake, dispatching Horst Neumann, a former paratrooper, to serve as her courier. Neumann parachutes onto the Norfolk coast, where an Irish farmer and Abwehr asset named Sean Dogherty takes him in.

Bletchley Park, Britain's codebreaking center, intercepts Abwehr messages confirming the existence of German agents operating outside MI5's control. Vicary is assigned to find them. Working with his partner Harry Dalton, a former Metropolitan Police detective, Vicary traces the 1938 murder and deduces that a spy entered Britain under a Dutch alias, then killed Pymm to make that alias appear dead. He discovers that Boothby previously obtained information about Vogel's network from a captured German spy but withheld it, deepening Vicary's distrust.

Catherine engineers a seemingly accidental encounter with Jordan in the Kensington blackout. A romance develops. She spends nights at his home, and after he falls asleep, she opens his safe using a combination provided by Vogel and photographs classified documents. She passes the film to Neumann, who delivers it to a Portuguese embassy contact for transmission to Berlin. When Rose Morely, a former cook in Catherine's family household who recognizes her on a London bus, threatens to expose her, Catherine follows Rose into Hyde Park and kills her.

Vicary's investigation connects the spy to the murder of London crime boss Vernon Pope, whom Catherine killed after Pope attempted to blackmail her. Vernon's brother Robert confirms that a woman calling herself Catherine hired them to surveil an American naval officer. When Vicary learns Jordan is assigned to Operation Mulberry, the scope of the disaster becomes clear: Plans for the artificial harbors may have reached Berlin.

At an emergency meeting with Churchill and Eisenhower, Vicary proposes allowing Jordan to continue seeing Catherine while MI5 controls the contents of his briefcase. The doctored documents, produced under the code name Kettledrum, depict the Phoenix caissons as components of an antiaircraft complex bound for Calais. Jordan reluctantly agrees. Vicary's team bugs Jordan's house and begins feeding Catherine disinformation.

The operation runs for several weeks. Vogel presents the intelligence to Hitler, whose analysts offer competing interpretations. Despite the Kettledrum material supporting the antiaircraft theory, Hitler favors his instinct that Mulberry is an artificial harbor destined for Normandy. Vogel orders Neumann to check whether Catherine is being watched. Neumann spots MI5 watchers and alerts Catherine. They realize that if Jordan is cooperating with British Intelligence, everything in his briefcase is false, and the disinformation may reveal the invasion's real target. Neumann devises an escape plan: steal a vehicle, drive to the Lincolnshire coast, and rendezvous with U-509, a German submarine offshore.

When Special Branch storms Catherine's flat, Neumann arrives through the rear entrance and a firefight erupts. Harry wrestles away Catherine's suitcase radio, but the spies escape. A nationwide manhunt follows. At the Dogherty cottage on the Norfolk coast, Martin Colville, a neighbor suspicious of Neumann, bursts in with a shotgun and kills Dogherty. Catherine and Neumann kill Colville, take his daughter Jenny as a hostage, and flee toward Lincolnshire.

After killing four constables at a roadblock, the fugitives reach the coast, steal a fishing boat called the Camilla, and head into the stormy North Sea. Jenny, bound below decks, frees herself and uses a hammer to sever the boat's fuel lines, disabling the engine as U-509 surfaces nearby. A Royal Navy corvette spots the scene and opens fire. Catherine and Neumann are killed. The submarine dives and escapes. The Camilla capsizes, throwing Jenny into the freezing sea. Peter Jordan dives from a police boat and rescues the unconscious girl but is dragged under by the capsizing vessel and drowns.

Vicary is forced out of MI5. Months later, he summons Boothby and learns the devastating truth: The entire operation was designed by MI6 (Britain's foreign intelligence service) from the start. Walker Hardegen, Bratton Lauterbach's top lieutenant at the bank, had been a controlled double agent all along, and Jordan was recruited specifically as a channel to feed the Abwehr false intelligence. Canaris himself had revealed Vogel's network to MI6, enabling the British to design the Kettledrum trap. Vicary was chosen as the unwitting case officer because his intelligence, his friendship with Churchill, and his antagonism toward Boothby would make the operation appear authentic to German observers. His sacking, communicated to Berlin through a covert network of double agents secretly controlled by Boothby, served as final proof that the stolen documents were genuine. Even Vicary's Cambridge friend Brendan Evans helped design the operation using intimate knowledge of Vicary's psychology. On June 6, 1944, the Allies landed at Normandy with their plans intact.

In the novel's final scenes, set in May 1945, Vicary has returned to University College. He walks through a newly illuminated London, passes Helen's house and feels nothing, and boards a train to the countryside, at last finding something resembling peace.