Faceless

 
Over the centuries, a small clan of spies called the Tabula Rasa has worked ceaselessly to fight oppression. They can pass unseen through enemy lines and 'become' other people without being recognized. They are, essentially, faceless. Alice and Louise Winfield are sisters and spies in the Tabula Rasa. They're growing up in wartime England, where the threat of Nazi occupation is ever near. But Louise wants to live an ordinary life and leaves the agency. Now, as Alice faces her most dangerous assignment yet, she fears discovery, but, most of all, she fears losing her own sister.