“Then Nitta was embezzling,” Sano inferred.

Toda nodded, gazing over the walls at the rooftops of the palace stables. A flock of crows perched in the pine trees. “There have been discrepancies between tributes sent from the provinces and the money in the treasury accounts. After we investigated, our suspicion settled on Nitta. He’d always been honest before, but Yoshiwara is an expensive habit. We placed him under secret surveillance and observed him taking gold from the storehouse at night. He alters the entries in the account books to hide the missing money.”

The agent gave Sano a sharp glance. “How does Nitta’s embezzlement fit into the murder case? Is he a likelier suspect because of it?”

“That’s possible,” Sano said. “Maybe he killed Wisteria because he regretted telling her about his embezzlement and wanted to prevent her from reporting him. Even if she didn’t have proof, and she was just a prostitute, her accusation could have hurt him.”

“Perhaps Wisteria told Lord Mitsuyoshi,” said Toda. “In his hands, the knowledge could have been most dangerous to Nitta because he and Mitsuyoshi were on bad terms. Nitta wrote a report about how much money Lord Mitsuyoshi squandered and sent it to his family. His father was shocked by his extravagance, and cut his allowance. Mitsuyoshi blamed Nitta for impoverishing him. He believed Nitta did it so he couldn’t afford appointments with Wisteria.”

They reached the end of the racetrack and turned, retracing their steps. The crows swooped over the meadow like black kites, their caws loud in the still air. Sano pondered the fact that Toda had just contradicted the treasury minister’s claim that he didn’t love Wisteria and wasn’t jealous of her other clients, but confirmed Senior Elder Makino’s statement. “Then you think Nitta killed Mitsuyoshi and Wisteria both?”

“He could be behind the murder and her disappearance,” Toda said, “but he’s not the type to dirty his hands by stabbing a man or abducting a woman.”

“Could his retainers have done the dirty work?” Sano said.

“Unlikely. They’re loyal to Nitta, but I doubt if their obedience extends to murdering the shogun’s heir. Nitta has a wide acquaintance among the ruffians he meets in Yoshiwara. If I were you, I’d look into them.”

Sano would. Yet he had misgivings about the scenario he and Toda had devised. “If Wisteria was murdered in her room, there should have been some evidence of it, but I found no indication that anyone except Mitsuyoshi had died there. If she was abducted then killed someplace else, where is her body?”

“I understand you’re still searching the area around Yoshiwara, and along the highways,” Toda said.

“We’ve yet to find a corpse.”

“She could have been dumped in the Sumida River, the Sanya Canal, or one of the smaller waterways.”

But Sano’s instincts told him that Wisteria was alive, and he had additional reason to discount the likelihood of her murder. The pillow book provided a scenario that didn’t involve the treasury minister, and indicated that Wisteria’s disappearance had been a voluntary elopement. However, Sano understood that even if the book was genuine, and Lady Wisteria had written the truth in the pages he’d read, they were only part of the whole book. Perhaps the unnamed lover from Hokkaido was just as possessive toward Wisteria and jealous of her clients as Nitta seemed. Perhaps he’d murdered the last client she’d entertained before they left Yoshiwara.

“You might be interested to know that Treasury Minister Nitta was arrested early this morning,” Toda said.

“What?” Sano halted in surprise.

“For his embezzlement,” Toda explained. “By now, his trial should be underway.” With a sly smile, Toda added, “If you need any further information from him, you’d best get over to Magistrate Aoki’s Court of Justice.”

“But my investigation isn’t finished. Nitta can’t be tried now.” Sano knew what would happen to the treasury minister. That Nitta had earned his fate didn’t ease Sano’s horror. Sano urgently beseeched Toda, “Please call off the trial!”

“I’m sorry, but the matter is out of my hands.” Shrugging, Toda contemplated the crows. They alighted in a black horde in the meadow, where they squawked and fluttered, squabbling over some bit of food. “And I venture to say that the murder investigation is out of yours.”

Hirata’s family home was in the bancho, the district west of Edo Castle where the Tokugawa hatamoto occupied estates surrounded by live bamboo fences. Although these vassals had served the shogun’s clan long and faithfully, they lived in conditions modest at best and often near poverty because of rising prices and the falling value of their stipends. Today the crowded neighborhood of ramshackle buildings looked drab indeed, with the bamboo withered and leafless. Hirata rode amid other samurai, along narrow, muddy dirt roads. He dismounted outside his parents’ house, one of the poorest in the district.

Entering the plain wooden gate, Hirata found the courtyard occupied by four horses, decked with fancy saddles and bridles, which didn’t belong to his family. Three of his small nephews raced around the side of the low, weathered house, shouting. Hirata secured his own horse and went into the house. When he hung his swords in the entryway, he noticed four ornate sets of swords, presumably belonging to the visitors, on the racks with the plain weapons of his father and grandfathers. He entered the corridor and found the house full of people and noise. His grandmothers sat in the main room, smoking while they scolded the toddlers playing near them. Hirata heard the maids banging dishes in the kitchen, and a baby crying. Every time he came home, the place looked smaller and dingier. Today it was also chilly because his family needed to conserve fuel. Greeting his grandmothers, Hirata experienced guilt that his kin must endure this, while he enjoyed the quiet luxury of Sano’s estate.

His eldest widowed sister came carrying the baby. “How nice to see you, Brother,” she said. “Many thanks for the clothes you sent the children.”

Spending most of his stipend on his family didn’t ease Hirata’s guilt. Before he could ask who was visiting them, his father’s voice called from the parlor: “Is that you, Son? Please come in.”

Curious, Hirata obeyed. In the parlor sat his parents and a middle-aged samurai garbed in opulent robes. Near the samurai knelt three men in plainer dress, evidently his retainers. Hirata’s mother was serving tea with her best utensils.

“How fortunate that my son should arrive while you’re here,” Hirata’s father said to the guest, then turned to Hirata. “You remember the Honorable Yoriki Okubo.”

“Of course.” Hirata knelt beside his father and bowed to the guest. Yoriki Okubo had been his commander when he was a police officer, and his father had served under Okubo’s. But the two clans had never been on intimate terms, and Hirata wondered why the yoriki had come. He said politely, “It’s an honor to see you again. I hope you are well?”

“Yes, thank you.” Yoriki Okubo had fleshy, down-turned features. He observed Hirata with shrewd approval. “I can see that you are also well. Life in the sōsakan-sama’s employ suits you.” After questioning Hirata about his duties, Okubo said, “That you make time in your busy day to visit your parents is a mark of good character.”

Hirata cast a puzzled glance at his father, who avoided his eyes and addressed Okubo: “My son is always conscientious about his duties to both his master and his family.” Still without looking at Hirata, his father said to him, “Okubo-san has come on behalf of his colleague, the Honorable Yoriki Sagara.”

“My colleague has an unmarried daughter,” Okubo said.

Alarm struck Hirata as he comprehended that Okubo was here as a go-between, bearing him a marriage proposal from the other police commander. Since his parents clearly welcomed the proposal, it was obvious that they’d rejected the idea of his marriage to Midori.