The story is based on the work of female spies during WWI. The book recounts the danger under which these women were engaged to spy on the Germans. Fictional characters are interspersed with accounts of actual spies. The most significant of the actual spies was Lili, the “queen of the spies” who managed a large network of secret agents “right under the nose of the enemy”. The fictional Eve Gardener was one of the WWI spies who was tortured and imprisoned for her work against Germany. Several decades later, in the aftermath of WWII an American girl (Charlie) was led to Eve to try to help find her cousin who disappeared, but was linked to some of the people from Eve’s past life. Charlie and Eve became unlikely friends over the dangerous search for Rose, a search that helped Eve to resolve the conflicts over her betrayals in the earlier war.