“I’ve been expecting this,” Hirata told Sano.

“It was only a matter of time,” Sano agreed.

As the shogun’s sōsakan-sama-most honorable investigator of events, situations, and people-Sano usually occupied himself with investigating important crimes and advising his lord, Tokugawa Tsunayoshi, dictator of Japan. But during recent months he’d spent much time keeping order amid the political upheaval in Edo. The bakufu-the military government that ruled Japan -was divided by a struggle for control of the Tokugawa regime. One faction, led by the shogun’s second-in-command, Chamberlain Yanagisawa, opposed a second led by Lord Matsudaira, a cousin of the shogun. Other powerful men, including the daimyo-feudal lords-had begun taking sides. Both factions had started building up their military forces, preparing for civil war.

Soldiers had poured into Edo from the provinces, crowding the barracks at daimyo estates and Edo Castle, overflowing the district where Tokugawa vassals lived and camping outside town. Although Chamberlain Yanagisawa and Lord Matsudaira hadn’t yet declared war, the lower ranks had grown restless. Idle waiting bred battle fever. Sano and his detective corps had already quelled many skirmishes. Now, the city elders who governed the townspeople had sent Sano an urgent message begging him to come and quell this major disturbance that threatened to shatter the peace which the Tokugawa regime had maintained for almost a century.

“Let’s break up this brawl before it causes a riot and wrecks the town,” Sano said.

“I’m ready,” Hirata said.

As they forged through the crowd, leading their troops, Sano recalled other times they’d ridden together into battle, when he’d taken Hirata’s competent, loyal service for granted. But last summer, while they were attempting to rescue the shogun’s mother and their wives from kidnappers, Hirata had disobeyed Sano’s orders. Now Sano could no longer place his complete trust in Hirata.