“That again?” Kusanagi grimaced. “Who cares? We’ll find out soon enough when the killer confesses. Even Yukawa’s accepted that.”
“Professor Yukawa?”
“I saw him last night.”
Kusanagi told Utsumi about meeting with Yukawa at the trendy local bar.
“Now that we’ve found physical evidence, we need to push things forward hard and fast. I intend to throw all the manpower we’ve got at this problem. We’ll do whatever it takes to find the person who transported the helium tank from the park to the crime scene.”
After delivering this rousing speech, Kusanagi consulted his watch. Now that the investigation task force was officially up and running, Director Mamiya was supposed to put in an appearance.
We need to be able to report some progress. Otherwise I won’t be able to look him in the eye, he thought to himself.
26
Detective Sergeant Utsumi took a deep breath as she looked up at the imposing gray building. She didn’t know why she was feeling so nervous. Even when she interrogated the toughest of criminals, she was never this anxious.
As she walked up to the front entrance, her eyes were drawn to the metal plaque on the walclass="underline" TEITO UNIVERSITY METALS MATERIALS RESEARCH INSTITUTE. The sans serif font felt cold and aloof. To her, it seemed to be looking down on the visitors.
She went in. There was a small office on the right, with a gray-haired guard sitting inside. She filled out the form he handed her and slipped a lanyard and visitor pass over her head. When she asked for directions, the reply was terse and ungracious: “Third floor, far end,” the guard said.
She rode the elevator to the third floor and made her way down the long corridor. There was a whole series of doors. On one of them was a sign that read MAGNETISM RESEARCH SECTION, and beneath that RESEARCH LABORATORY 1 and RESEARCH LABORATORY 2. Kaoru was supposed to go to the Magnetism Research Section: Chief Research Officer’s Room.
Utsumi took another deep breath and knocked on the door.
“Come in.” Utsumi felt a twinge of nostalgia when she heard the resonant voice.
“Hello?” She pushed the door open. In front of her was some armchairs and beyond that, a desk. The person sitting at the desk spun briskly around in his chair. “Very nice to see you.”
There was a moment’s silence. “It’s been a long time,” Utsumi said with a little bow.
Manabu Yukawa rose slowly to his feet.
“I wasn’t expecting you to get in touch. With the task force up and running, I thought you’d be too busy.”
“You’re right. As I said in my message, my visit today is much more than a simple courtesy call.”
“Let’s get straight down to business, then.” Yukawa dropped into one of the armchairs and motioned with his open palm for her to sit in the one opposite.
“Thank you,” said Kaoru, sitting down. “Has our unit chief explained to you how Kanichi Hasunuma was killed?”
“When you use terminology like ‘unit chief,’ I’m not quite sure who you’re talking about.” Yukawa narrowed his eyes behind his lenses. “Yes, Kusanagi told me: the combination of helium gas and a plastic bag.”
“What do you think?”
“Think? If you mean, do I think it’s scientifically plausible? Then yes, I do.”
“It was slightly different from your own theory, Professor.”
“There’s nothing odd about that. In science, we create hundreds of hypotheses, most of which end up being proved wrong.”
“Don’t you have any doubts about it?”
“Doubts? In what way?”
“Doubts about that method.”
Yukawa’s jaw twitched and his eyes became cold and rational. He looked hard and appraisingly at Utsumi.
“What is it?”
“Kusanagi told me. That you were critical of the method of killing. That you couldn’t understand the point of anything so grandiose and convoluted.”
“Yes, but I was prepared to accept it after Chief Kusanagi explained the theory to me in greater detail. The method of killing you deduced, Professor, came with real advantages for the killer. As for the deduction that the small room where the crime took place was a substitute gas chamber — that is the sort of idea that only you could have come up with.”
“Nonetheless, ingenious though my deductions were, they were also wrong, so they mean nothing.”
“Wrong?... Do you really think so? I’m inclined to think you were right, Professor.”
Yukawa was breathing hard and his chest was visibly rising and falling. He fixed his eyes on Kaoru. “Why do you say that?”
“First, there’s the issue of the nature and quantity of the sleeping medication. Based on the traces that were found in Hasunuma’s bloodstream, the sleeping medication he took wasn’t very powerful; nor did he take it in any significant quantity. If he was asleep, his state was far from comatose. He would probably have woken up if anybody had touched him. In terms of making sure that he wouldn’t wake up while the crime was in progress, the method you proposed seems far likelier to succeed. I even think that the killer might have deliberately made a lot of noise specifically in order to wake Hasunuma up after locking the sliding door.”
“Deliberately woken him up?” Yukawa frowned. “What for?”
“To frighten him.”
“To frighten him.” Yukawa gazed at Utsumi admiringly and straightened himself against the back of his chair. “That’s certainly novel.”
“I was working on the hypothesis that the motive in the Hasunuma killing was revenge. I tried to imagine how I would take revenge if someone had murdered a member of my family. I certainly wouldn’t slip a plastic bag over anyone’s head and use helium to kill them through oxygen deficiency. And the reason is not because it’s too convoluted or troublesome. Why do you think it is?”
Yukawa shook his head. “I don’t know.”
“There’ve been a lot of articles on the internet recently about using helium to commit suicide. Do you know why?”
Yukawa thought for a moment. “Perhaps,” he murmured, “because you can die... comfortably?”
“Correct.” Utsumi gave a crisp nod. “If helium works fast, you can lose consciousness with your first breath and then go on to die from there. You barely suffer. But would anyone deliberately select a method like that to kill someone whom they hated? If it was me, I’d choose a method that caused maximum pain and fear.”
“There’s some truth—” said Yukawa, crossing his long legs. “No, I think there’s a great deal of truth in what you’re saying. It’s highly logical and persuasive.”
“That’s why I think your theory is right: The killer deliberately wakes Hasunuma up and only then does he start pumping the helium into the room. The oxygen concentration gradually goes down. Hasunuma starts to feel nauseous and gets a headache. He’s trapped. He’s got to be feeling intensely afraid.”
“In other words, it’s the perfect way to execute a cold-blooded killer. It’s a very original idea, but it does have one problem: the very large amount of helium required.”
“That’s what I thought, too.” Kaoru bit her lip. “Nobody helped themselves to one of the gas cylinders used for the giant inflatable mascot, and if the killer had bought a high-pressure cylinder, there’d be some trace of the purchase...”
Yukawa broke into a beatific smile.
“Is something wrong, Professor?”
“No, no. It’s just been a long time, so I’m feeling a bit sentimental. Here I am with a beautiful young lady detective theorizing her heart out in front of me.”
“I’m hardly young anymore.”
“But you’ll accept the beautiful label?”