A rueful smile touched Sano’s lips as he started toward the door. Twenty-one years old, Hirata took very seriously his role as chief retainer and primary protector, opposing Sano’s determination to fight battles alone and reserve the worst risks for himself. He didn’t know that his master’s unspoken fear of loss and guilt outweighed the fear of death. And he didn’t understand that Sano needed danger, and confrontation with evil. Bushido—the Way of the Warrior—taught that a samurai’s sole purpose was to give his life to his lord’s service. Duty, loyalty, and courage were its highest virtues, and together formed the foundation of a samurai’s honor. But Sano’s personal concept of Bushido encompassed a fourth cornerstone, as important to his honor as the others: the pursuit of truth and justice. The exhilarating quest for knowledge, the satisfaction of seeing a criminal caught and punished, infused his existence with a deeper purpose than serving a gravely flawed regime.

“Come on, let’s go,” Sano said.

With Hirata beside him, he stole up to the building, quietly slid open the door, and looked into a large room lit by hanging lanterns. Mounted on wall brackets were many sheathed swords, and gleaming steel blades with the hilts removed. Characters etched on the tangs certified that these blades had cut human bodies during tameshigiri, the official method of testing swords. In the back of the room, near sliding doors that opened onto a wet courtyard, stood seven men: the four thieves in dripping cloaks, the hoods thrown back from their coarse faces; two peasants in cotton headbands, loincloths, and short kimonos; and an older man dressed in a formal black surcoat and trousers stamped with the Miochin crest. In his pale, aquiline face, deepset eyes burned.

The thieves unwrapped the bundle on the floor, baring the corpse of a stout man shrouded in white silk funeral garments. Gazing down at it, Miochin said, “A perfect specimen. Many thanks.”

According to Tokugawa law, the bodies of executed criminals could be used to test swords, but murderers, priests, tattooed individuals, and eta were taboo. A recent shortage of suitable traitors, thieves, and arsonists had reduced the supply of raw material for sword testers. When the bakufu sold the few available corpses to the highest bidders among the hereditary testing officials, the wealthy Yamada, Chokushi, and Nakagawa families bought up the precious commodity, forcing minor clans such as the Miochin to use straw dummies. However, the cutting of human flesh and bone was the only true test of a blade’s quality. Since swords tested otherwise fetched lower prices and commanded less respect, Edo’s swordsmiths and samurai avoided testers who couldn’t certify their weapons at the highest level of strength. Miochin, unwilling to accept the loss of income, had hired rōnin to procure corpses by theft and murder.