“ ‘It said that his wife and a man who was Dannoshin’s own paramour had carried on a secret affair together. When Dannoshin found out, he decided to punish his wife by throwing her into the lake, then kill himself because he must atone for her death and could not bear that the two people he loved most had betrayed him with each other. The body of Anemone was never recovered.’ ”

Sano pounded his fist on the ledger as triumph exhilarated him. “This has to be the murder behind the kidnapping plot! Anemone is the drowned woman in the poem in the ransom letter. Since she was never found, she’s still in the lake, under the water-in the palace of the Dragon King.”

“But Hoshina didn’t kill Anemone,” said Toda. “Her husband did, according to his own confession. Why would anyone demand Hoshina’s execution for Anemone’s drowning? It makes no sense.”

“Maybe Hoshina still played a role in the murder,” Sano said. “I’m thinking he was the man who was the lover of both Dannoshin and Anemone.”

“Hoshina has been known to bed women, even though he prefers male partners,” Toda said. “If he was the lover, then Anemone’s death is indirectly his fault because her affair with him caused her husband to drown her.”

“Someone who grieved for her might resent the fact that Hoshina went about his business as if nothing had happened.” Sano reread the account. “Whoever wrote this neglected to mention the lover’s name.”

“Perhaps the omission was deliberate,” Toda said, then hinted, “What was Hoshina doing twelve years ago, when Anemone and Dannoshin died?”

“Hoshina was a detective on the Miyako police force,” Sano recalled. “Perhaps he investigated the deaths. There would have been an ugly scandal, and he probably wanted to keep himself out of it. He could have destroyed evidence that implicated him.”

“And made sure his name never appeared in any official records,” Toda said.

“Supposing he was indeed the third party in the triangle, there’s another reason for him to cover up the fact,” Sano said. “At the time, he was the companion of the shoshidai.” The shoshidai was the Tokugawa official who ruled Miyako, and a cousin of the shogun, “He wouldn’t have wanted his master to know he’d been indulging his lust elsewhere.”

“That might have cost him his position,” Toda said, “and his chance of rising in the bakufu.”

Exhaustion, as well as pressure to identify the Dragon King before noon and save Lady Keisho-in before the shogun lost patience and did something rash, took the edge off Sano’s triumph. Rubbing his tired eyes, he said, “This is all conjecture. And even though I’m sure that the Dragon King is someone connected with Anemone or Dannoshin, we still don’t know who he is, let alone where he is.”

“I’ll look up the names of their relatives,” Toda said. “I can also check on which are members of the bakufu and live in Edo. But it will take time to unearth the clan lineage records from the archives and match names on them to the thousands on the bakufu list.”

And time was running out for Sano. “Get your metsuke comrades to help you,” he said, rising to leave.

“Very well,” Toda said.

“Meanwhile,” Sano said, “I’m going to try a shortcut to the Dragon King. Knowing what we know now, I think a talk with our friend Hoshina is in order.”

The sun had ascended over Edo Castle, but the forest preserve cast deep shadow over the guard tower that imprisoned Hoshina. Although the morning was clear and the air windless beneath the hazy aquamarine sky, gray clouds spilled mist and rain over the distant hills, portending storms for the city. Sano strode toward the tower along the walkway on top of the palace wall. There, three guards lounged outside the door to the prison.

“Open up,” Sano said. “I want to see Hoshina-san.”

The guards obeyed. Sano stalked into the dim room, whose stone walls exuded the transient coolness of night. Hoshina lay asleep on his futon, with his back to Sano. When Sano kicked his buttock, Hoshina jerked awake, let out a cry of alarm, and clambered to his feet. Groggy panic showed on his face as he reached for the sword he normally wore, and his hand clutched empty air. Then he saw Sano. Even as his breath puffed from him in relief, anger stimulated him to alertness.

“Why did you wake me up like that?” he said. “To torment me for your own amusement?”

“We need to talk,” Sano said, his sympathy for Hoshina depleted by everything he’d learned about the man since yesterday.

“What’s happened? Have you found out something?” Hope of rescue enlivened Hoshina’s haggard, unshaven face. “Have you caught the person who got me into this predicament?”

Pressed for time, Sano forbore to argue that Hoshina’s own execrable behavior was the root of his troubles. “No, I haven’t caught the Dragon King,” Sano said, “but I’ve found out plenty. Why didn’t you tell me about Anemone?”

“Who?” Hoshina regarded Sano in genuine bewilderment. Then recognition encroached. “Oh. Anemone,” he said in the perturbed tone of a man suddenly confronted by a ghost from his past.

“So you were her lover?” Sano said. When Hoshina nodded, Sano said, “Were you her husband Dannoshin’s lover as well?”

Again Hoshina nodded, warily.

“Dannoshin drowned Anemone because you and she cheated on him by having an affair with each other,” Sano said. “Were you the detective who investigated their deaths? Did you cover up your part in them to protect yourself from scandal and punishment?”

“Yes, but what has that got to do with anything?” Hoshina said, annoyed now.

Incredulity filled Sano as he beheld Hoshina. Did the man really not understand the significance of the events? “It’s a murder connected with you, that you should have mentioned when we made the list yesterday.”

“But we were focusing on people I killed, or sent to their execution,” Hoshina said, hands on his hips and feet planted wide in defensive obstinacy. “I didn’t kill Anemone. She didn’t belong on that list.”

“One might argue that you were indirectly responsible for her death,” Sano pointed out.

“I wasn’t responsible. Her murder was her husband’s doing, not my fault. They were just a pastime for me. I couldn’t help it if he overreacted.” An aggrieved whine tinged Hoshina’s voice. “How did you find out about her, anyway?”

It was just like Hoshina to disclaim culpability, Sano thought in disgust. “Never mind how I found out. You should have told me about Anemone’s murder, instead of hiding a source of potential suspects.”

“I wasn’t hiding anything,” Hoshina protested. “I haven’t thought of Anemone in years. I didn’t mention her because I’d forgotten her.”

“She and her husband died because of her affair with you, and you didn’t even remember her?” Sano thought he’d already learned the worst about Hoshina, but there seemed no limits to the man’s callousness.

“All right, I should have remembered. I should have told you about Anemone.” Hoshina flung out his arms in a gesture of mock surrender and glared at Sano. “What are you going to do, kill me?”

“It’s tempting,” Sano said, “but I need your help. I’ve got an army of metsuke agents searching for information on people connected with Anemone and Dannoshin, but that will take too long. Here’s your chance to make up for the lost time that your bad memory has cost us. You knew Anemone and Dannoshin. Who in their household would have wanted to avenge her death?”

Hoshina’s features went slack with astonished dismay. “It was ages ago that I knew them. That time is a blur in my mind. How am I supposed to remember anyone in their household?”

“Try,” Sano said. “Your life may depend on your remembering.”

Pacing the room, Hoshina clamped his hands to his head, as though to physically squeeze out facts. “Dannoshin had a couple of sons from his previous marriage. They were in the Miyako militia. We were on friendly terms-I don’t think they had a grudge against me. Dannoshin’s parents lived in his house, but they were so old, they’re probably dead now. I can’t think of anyone else.”