The New York Times bestselling author of The Spy and the Traitor tells the thrilling true story of the most important female spy in history: an agent code-named “Sonya,” who set the stage for the Cold War.

In 1942, in a quiet village in the leafy English Cotswolds, a thin, elegant woman lived in a small cottage with her three children and her husband, who worked as a machinist nearby. Ursula Burton was friendly but reserved, and spoke English with a slight foreign accent. By all accounts, she seemed to be living a simple, unassuming life. Her neighbors in the village knew little about her.

They didn’t know that she was a high-ranking Soviet intelligence officer. They didn’t know that her husband was also a spy, or that she was running powerful agents across Europe. Behind the facade of her picturesque life, Burton was a dedicated Communist, a Soviet colonel, and a veteran agent, gathering the scientific secrets that would enable the Soviet Union to build the bomb.

This true-life spy story is a masterpiece about the woman code-named “Sonya.” Over the course of her career, she was hunted by the Chinese, the Japanese, the Nazis, MI5, MI6, and the FBI—and she evaded them all. Her story reflects the great ideological clash of the twentieth century—between Communism, Fascism, and Western democracy—and casts new light on the spy battles and shifting allegiances of our own times.

With unparalleled access to Sonya’s diaries and correspondence and never-before-seen information on her clandestine activities, Ben Macintyre has conjured a page-turning history of a legendary secret agent, a woman who influenced the course of the Cold War and helped plunge the world into a decades-long standoff between nuclear superpowers.