In the aftermath of World War II, Charlie St. Clair is pregnant and unmarried. When her parents banish her to Europe so she can terminate her pregnancy, Charlie instead heads to London to find out what happened to her cousin Rose, who disappeared in Nazi-occupied France during the war. A year into World War I, Eve Gardiner is recruited to work as a spy. Sent into enemy-occupied France, she is trained by Lili, who manages a vast network of secret agents. Thirty years later, Eve is still haunted by the betrayal that ultimately tore apart the Alice Network. But then a young American barges into her crumbling London house and utters a name she hasn't heard in decades, launching them both on a mission to find the truth, no matter where it leads.