There was only one way to put Yasuko and her daughter truly at peace. He would have to detach them completely from the case. He would make it seem as though they were connected, and yet there could be no doubt that they had nothing to do with the murder.
That was when he decided to use the Engineer—the homeless man who had so recently begun living at the camp near Shin-Ohashi Bridge. It all worked quite smoothly.
In the early morning of March 10, Ishigami had approached the Engineer. He had found him sitting apart from the other homeless as usual.
“I have a job for you,” Ishigami had told the man. He explained that he wanted him to help as an observer on a riverworks project that would last several days. He had noticed that the Engineer had a background in construction.
The Engineer had been suspicious at first. “Why me?” he had asked.
“Well,” Ishigami had explained, “I’m in a bit of a tight situation.” And he’d told how the man he had previously asked to observe had been in an accident and was now unable to do the job—and, without an observer there, his firm wouldn’t get permission to proceed with the work. He needed someone to stand in for the absent man.
He’d offered an advance of fifty thousand yen, and the Engineer had agreed. Ishigami had then taken the man to the rental room where Togashi had been saying. There he’d given him Togashi’s clothes to put on and had told him to sit tight until that evening.
When evening came, he’d brought the Engineer out to Mizue Station. Ishigami had stolen a bicycle from Shinozaki Station in advance. He had chosen the newest bicycle he could find, to assure that the owner would promptly report the theft.
He had prepared another bicycle as well. This one he had stolen from Ichinoe, the station before Mizue. It was an old bicycle, with a broken lock.
He’d given the new bicycle to the Engineer, and the two of them had gone to the river, soon arriving at the spot along the Old Edogawa.
Remembering what happened next made Ishigami’s heart fill with darkness. The Engineer never knew why he had to die.
Ishigami couldn’t have anyone know about the second murder—especially not the Hanaokas. That was why he had used the very same murder weapon and had strangled the victim in the very same way.
Togashi’s body he had cut into six parts in his bathtub, tossing each one separately into the Sumida River in bags weighted down with heavy rocks. He did this all under cover of darkness, in three separate locations on three separate nights. He knew that at least some of them would be found at some point, but he didn’t care. The police would never be able to learn to whom the body parts belonged. According to their records, Togashi would have already been dead and his body found—and a man couldn’t die twice.
He was pretty sure that only Yukawa had figured it all out. Which was why Ishigami had chosen to turn himself in to the police. This, after all, was something he had been ready to do from the very beginning, and for which he had already made the necessary preparations.
Yukawa would talk to Kusanagi. Kusanagi would then inform his superior. But the police wouldn’t act. At that point, there would be no way to prove they had misidentified the body. Meanwhile, Ishigami would be charged with Togashi’s murder.
There was no turning back now. Nor was there any reason to stop the plan he’d set in motion. No matter how brilliant the deductions of that genius physicist might be, they had no hope of prevailing against an actual criminal’s confession in court.
I’ve won, he thought.
He heard a buzzer sound. It was the signal that indicated that there were visitors to the holding cell. The guard rose from his chair.
After a brief negotiation, someone entered the cell area. It was Kusanagi. He waited in front of the bars while the guard ordered Ishigami from his cell. The mathematician was searched, then handed over to Kusanagi. The detective didn’t say a word while all this was happening.
Outside the holding cell, Kusanagi turned to Ishigami and asked, “How are you feeling?”
Ishigami couldn’t tell whether it was the detective’s custom to be polite, or if this was part of some ploy.
“A little tired, to tell the truth. To be honest, I’d like to get through the legal proceedings as quickly as possible.”
“Don’t worry, this will be last time I’ll be taking you out for questioning. There’s someone here to see you.”
Ishigami frowned. Who could it be? Not Yasuko, he hoped.
Kusanagi led him to the interrogation room and opened the door. Manabu Yukawa sat inside. He stared at Ishigami, a pensive look on his face.
The final hurdle, Ishigami thought, bracing himself.
For a time, the two geniuses sat across the table from each other in silence. Kusanagi leaned against the wall, keeping an eye on them.
“You’re looking a little thin,” Yukawa said at last.
“Oh? I’ve been eating fine.”
“Good to hear. I wanted to ask you,” Yukawa licked his lips. “Aren’t you embarrassed at all to be labeled a stalker?”
“But I’m not a stalker,” Ishigami replied. “To the contrary, I’ve been protecting Yasuko Hanaoka, though not openly. I’ve told the police this several times already.”
“I know what you told them. And I know you continue to protect her even now.”
Ishigami looked displeased and glanced up toward Kusanagi. “How is this discussion going to help your investigation?”
Kusanagi said nothing.
“I told him what I know,” Yukawa said. “I told him what you really did, and who you really killed.”
“I’m sure you’re free to discuss your conjectures with whomever you wish.”
“I’ve also told her—Yasuko Hanaoka.”
The skin of Ishigami’s cheeks drew taut across his face. But he soon managed a thin smile. “Did she show some remorse, maybe? Was she thankful to me? From all I’ve heard, she’s been going on like I did nothing for her—like I never got rid of that thorn in her side.”
Kusanagi swallowed, watching Ishigami’s face twist as he played the role of spurned stalker to perfection. He hadn’t realized it was possible for anyone to devote himself so utterly to another. It was as impressive as it was terrifying.
“You seem to be suffering under the belief that as long as you don’t tell the truth it will never come to light, but you’re not entirely correct,” Yukawa said. “A man went missing on March 10. An innocent man, guilty of nothing. If we were to find out who he was, and find his family, we could do some DNA testing. Compare those results with the results from the body thought to be Shinji Togashi, and we’ll know the truth.”
“I’m not sure what you’re going on about,” Ishigami said, smiling. “But whoever this man you mentioned was, he probably didn’t have a family. And even if there was some other way of finding out who he was, it would take a staggering amount of time and effort to do so. By the time you’re done, I will already have been tried and convicted. Rest assured I’ll plead guilty. Once the verdict is announced, the case will be closed. The murder of Shinji Togashi will have been solved. The police’s hands will be tied. Or maybe—” He looked at Kusanagi. “Maybe you’ll listen to this guy’s story and change your mind about charging me. Which means you’d have to let me go. But on what grounds? Because I’m not a criminal? I assure you, I am. I’m a confessed murderer.”
Kusanagi looked down at the floor. It was true. As long as they couldn’t prove Ishigami’s confession false, it was impossible to stop the legal proceedings. That wasn’t how the system worked.
“There’s one thing I need to tell you,” Yukawa said.