1947. In the chaotic aftermath of World War II, American college girl Charlie St. Clair is pregnant, unmarried, and on the verge of being thrown out of her very proper family. She's also nursing a desperate hope that her beloved cousin Rose, who disappeared in Nazi-occupied France during the war, might still be alive. So when Charlie's parents banish her to Europe to have her “little problem” taken care of, Charlie breaks free and heads to London, determined to find out what happened to the cousin she loves like a sister.

1915. A year into the Great War, Eve Gardiner burns to join the fight against the Germans and unexpectedly gets her chance when she's recruited to work as a spy. Sent into enemy-occupied France, she's trained by the mesmerizing Lili, code name Alice, the “queen of spies,” who manages a vast network of secret agents right under the enemy's nose.

Thirty years later, haunted by the betrayal that ultimately tore apart the Alice Network, Eve spends her days drunk and secluded in her crumbling London house. That is until a young American barges in uttering a name Eve hasn't heard in decades, and launches them both on a mission to find the truth . . . no matter where it leads.