May 1695. During a horse race at Edo Castle the chief of the shogun's intelligence service, Ejima Senzaemon, drops dead as his horse gallops across the finish line-the fourth in a recent series of sudden deaths of high-ranking officials. Sano Ichiro is ordered to investigate, despite his recent promotion to chamberlain and his new duties as the shogun's second-in-command. Meanwhile, Sano's wife...