Utsumi gave a curt bow and made as if to leave the room. Just before reaching the door, she stopped and turned around. Something was obviously on her mind.
“What’s the problem?” Kusanagi asked.
“Why opt for such a complicated method?” asked Utsumi, a disgruntled look on her face. “First knock him out by getting him to ingest sleeping medication, then asphyxiate him by pumping helium into a sealed room. Isn’t the whole thing a bit convoluted, a bit grandiose?”
“What?” Kusanagi looked at Utsumi with open surprise. “That’s not like you. Have you got your doubts about Yukawa’s theory?”
“It’s not so much that. It’s more that I can’t see what the perpetrator was trying to accomplish.”
“My guess is that he wanted to make it hard for us to pinpoint the cause of death. Hasunuma’s preliminary death certificate says that the ‘possibility of cardiac failure of unknown origin cannot be ruled out.’ Because we haven’t got proof that it was a murder, we haven’t been allowed to set up a proper investigation task force.”
“If we were talking about anyone else, I might be able to accept that. But this is Hasunuma we’re dealing with! The dead man is the one and only Kanichi Hasunuma.”
“What are you trying to say?”
“That unless the killer was hopelessly naive, he would expect the police to launch a murder investigation, whether or not they could identify the cause. Given that, why not opt for a simpler murder method?”
Kusanagi had no answer. Detective Utsumi’s argument was logical and cogent.
“You think that the elaborateness of the killing method may imply something else?”
“I think it’s possible.”
“Okay,” Kusanagi said. “I’ll be sure to keep that in mind.”
Utsumi bowed briskly and left the room.
About two hours later, Kishitani returned to the meeting room. He looked rather downcast and the news he gave Kusanagi was disappointing.
None of the helium cylinders used to inflate the giant mascot were missing.
“It took four seven-thousand-liter cylinders to inflate the Kikunon balloon. The empty cylinders were collected by the gas merchant the day after the parade, the same as they are every year.”
“Could somebody have stolen one of the cylinders and then replaced it later?”
Kishitani shook his head. “The person responsible for Kikunon was at his post all day.”
“I see.” Kusanagi clicked his tongue in frustration.
Maybe Muto was right, he thought. Maybe buying gas is easier than stealing it; it’s certainly less risky.
“Get in touch with any businesses that sell helium. See if anyone’s bought any recently under a false name.”
“Yes, sir,” Kishitani said. He was about to leave the room, when the door burst open and Muto came rushing in, his face slightly flushed.
“Chief Inspector, I found it.”
“Found what?”
“The tank. I found the helium tank.”
24
Behind the counter, the silver-haired bartender was solemnly polishing glasses as he stood in front of a wall covered with an array of different bottles: whiskey, brandy, vodka, and tequila. Kusanagi should be able to enjoy a variety of good, strong tipples.
It was nearly 11 P.M. A couple had just left a moment ago and now he was the only customer in the bar.
He was inspecting the old film posters on the walls and was about halfway through his pint of Guinness, when the street door creaked slowly open and Yukawa strolled in.
Kusanagi waved.
Yukawa ran his eyes around the bar with evident curiosity, before making his way to the small table where Kusanagi was sitting.
“I would never have expected to find a trendy place like this here in Kikuno,” said Kusanagi, as Yukawa himself sat down opposite him. “I asked one of the guys at the police station if there was anywhere good for a quiet drink that stayed open late, and this was the place he recommended. They have got all sorts of different brands.”
If you go a few times and the bartender gets a sense of what you like, he’ll probably create a special, original cocktail just for you, Muto had said when describing the place to Kusanagi.
Yukawa inspected all the various bottles lined up on the shelves behind the bar before making his order: “Ardbeg and soda, please.”
The silver-haired bartender narrowed his eyes approvingly. “Very good, sir,” he said.
“Were you doing your research this late at night? You’re seriously busy,” Kusanagi said.
“Not really. At the moment, I’m getting my assistants to conduct this experiment for me. It’s been dogged with problems and it failed to produce any of the data I was expecting to spend today checking. Since I had nothing to do, I just played chess against my office computer. My opponent was only a first-generation program, but my record was still dismaclass="underline" played three, lost three. It’s not easy for an amateur to win against AI.” Yukawa shrugged and sighed.
“A hard day at the office, then.”
“Speak for yourself. Anyway, what are you doing in Kikuno at this time of night? Are you staying here now?”
“Yes. Looks like I’ll be staying here for a while.”
Yukawa blinked uncomprehendingly.
“The text you sent me said you wanted to thank me in connection with the investigation and that I should get in touch, if I was here in Kikuno. Was my advice some use to you, then?”
“Extremely useful.” Kusanagi pointed a finger at Yukawa’s chest. “Good old Detective Galileo. You’re just as perceptive as ever. Your theory was about half right.”
“Only half?” Yukawa knit his brows doubtfully. “Then I was wrong about something?”
“You were right about the use of helium. We found the tank. It wasn’t one of the large high-pressure cylinders used for the giant inflatable.” Kusanagi pulled his phone out and pulled up a photograph. “There’s a river running behind the warehouse where the crime scene is located. The investigators from the Kikuno Police Station found it. It had been dumped in a patch of weeds on the riverbank about sixty feet from the warehouse.”
The photo showed a small tank about fifteen inches high and twelves inches wide. Someone had put a beer can next to it to give a sense of scale.
“The tank was empty. All the helium in it had been used. There were several sets of fingerprints on it. We’re in the process of getting them checked.”
“This thing?” Yukawa was looking at the picture with his head tilted to one side. “How many of them?”
“How many what?”
“Tanks. How many tanks like this did you find?”
“Just the one. Should there be several of the things?”
“One? That simply makes no sense,” Yukawa said forcefully, just as the bartender came gliding over. He slipped a coaster onto the table and placed a tumbler on top of it. Fine bubbles danced in the amber liquid.
Yukawa took a sip. A benign expression spread across his face. He looked up at the bartender. “Delicious. You got the proportions just right.”
The bartender smiled happily and went back behind the counter.
Yukawa put the tumbler down and pointed at the phone on the table. “I’m just asking this to be sure. What’s the capacity of that tank?”
Kusanagi took his notebook out of his pocket. “It weighs roughly six and a half pounds. A full new tank contains around four hundred liters.”
Yukawa gave a derisive snort. “Ridiculous. That’s impossible.”
“How so?”
“We need to start by calculating the volume of the small room at the crime scene. Let’s say that it’s about eight feet wide, six and a half feet deep, and six and a half feet high. That would come to a volume of ten thousand liters. Would pumping in a paltry four hundred liters of helium cause death from oxygen deficiency? Hardly. To kill someone, you would need to use high-pressure, industrial-use helium cylinders. They would be difficult to purchase under a false name. That’s why I suggested that the killer might have ‘borrowed’ a gas cylinder from the giant inflatable.” Yukawa was speaking rather faster than usual. Kusanagi wondered if he was annoyed.