Inspired by a true story, Red Joan captures the exciting revelation of a woman’s sacrifice in the face of incredible circumstances. In the 1930s, young Joan Stanley, a Cambridge student, falls in love with an attractive Russian diversionist, Leo. Joan, sympathetic to the Soviet and Communist Party, is employed as a public servant of the British government and is recruited by the KGB in the mid-1930s. During the Second World War, Joan gets to work for a highly secret nuclear research institution, and soon faces more difficult choices in terms of national loyalty, belief systems, and personal life. Remaining undetected as a spy for over half a century, it successfully transfers the secrets of the Soviet Union nuclear bomb, which allows them to keep up with the West in the development of atomic weapons.