Two agents—and former lovers—must work together to combat international cyberattacks threatening the UK while also confronting the buried secrets of their destructive relationship.

For Ursula Gothe, the wife of the up-and-coming engineer Dr. Richard Gothe, life in the post-war period is finally back on track. That changes when she rediscovers her daughter Martina, who she thought was dead, in a wanted ad. Ursula is stunned with joy, but also very scared: the girl is from a man she met during the war, before her time with Richard. Now Richard is about to be promoted to factory manager and does not want to be discredited because of an illegitimate child.