When her brother signs up for the front lines of World War 1, Jean looks for a way to bring him home. At her local book club, there is a talk about spy work to help injured soldiers escape across the Channel and Jean seizes her chance. She signs up with her her friend Eve, going through an exhausting training regime, before being sent to France to extract information from the German soldiers. But Eve’s husband wants to know where she keeps going and Jean is too deep undercover to get away from the soldiers.
