The year is 1916 and the world has been swallowed by a war greater than any before it. Amidst the tumult, Lillian Sinclair trains as a spy for the Deuxième Bureau, French intelligence. Sooner than anticipated, Lillian is given her first assignment: she must rescue a fellow agent, one who has spent months gathering information in enemy territory. To make matters worse, she's been assigned a difficult partner who she may not be able to trust. As she faces danger, Lillian's wit, courage, and heart will be tested.