The New York Times-bestselling novel depicting Nicholas Linnear's journey to track a savage serial killer A sadist haunts the back alleys and sex clubs of Tokyo, picking up women, horrifically mutilating them, and leaving behind a calling card written in blood: This could be your wife. He kills fearlessly, certain the police will never catch him. The only man who might stop this fiend is Nicholas Linnear, a martial arts expert whose childhood education in the dojos of Japan has made him one of the country's leading practitioners of ninjutsu. But Linnear fears that his illness may have left him Shiro Ninja-stripped of his power and discipline. With the killer growing increasingly more brazen, Linnear must summon all his strength and training before his own family becomes the next target.