On a whim of the shogun's mother, a procession has left the sweltering heat of Edo, bound for the cooler climate of Mount Fuji. Among her traveling companions are Reiko, the beautiful wife of Sano Ichiro, the shogun's Most Honorable Investigator of Events, Situations, and People; Reiko's friend Midori, nine months pregnant; and Lady Yanagisawa, the deranged wife of the shogun's powerful second-in-command. None of them look forward to the trip. But their troubles have only begun when their procession is stopped suddenly on a deserted road. The entire retinue is viciously slaughtered and the four women are bound and taken away, imprisoned by a mysterious kidnapper.
Sano now finds himself faced with the most important case of his career. The shogun demands quick action, and under the threat of death, Sano is forced to work with his bitter enemies-Chamberlain Yanagisawa and Police Commissioner Hoshina. The delivery of a ransom note only complicates matters-forcing both Sano and Reiko to take desperate measures.