In a strange room in Morocco, Mary Russell is trying to solve a pressing mystery: Who am I? She has awakened with shadows in her mind, blood on her hands, and soldiers pounding at the door. Out in the hive-like streets, she discovers herself strangely adept in the skills of the underworld, escaping through alleys and rooftops, picking pockets and locks. She is clothed like a man, and armed only with her wits and a scrap of paper showing a mysterious symbol. Overhead, warplanes pass ominously north. Meanwhile, Holmes is pulled by two old friends and a distant relation into the growing war between France, Spain, and the Rif Revolt led by Emir Abd el-Krim - who could be a Robin Hood, or a power-mad tribesman.