In a picturesque village in England, Joan Stanley (Academy Award winner Dame Judi Dench), lives in contented retirement—until her tranquil existence is shattered when she's arrested by MI5. Far from being a typical wife and mother, Joan has been hiding an incredible past: she is one of the most influential spies in living history.
At Cambridge University in the 1930s, the young Joan (Sophie Cookson) falls intensely in love with a seductively attractive Russian saboteur, Leo. Through him, she begins to see that the world is on a path toward destruction as countries race toward military supremacy. After World War II, working at a secret nuclear research facility, Joan found herself confronted with the impossible: Would you betray your country and your loved ones, if it meant saving them? What price would you pay for peace?
Inspired by an extraordinary true story, "Red Joan" is the taut and emotional discovery of one woman's life-changing choices in the face of incredible circumstances.