Salvation of a Saint

SEVENTEEN

According to the chart on the door, Yukawa was alone inside the laboratory – exactly as Utsumi had expected. She knocked on the door.

‘Come in,’ came the curt reply. She entered to find Yukawa in the middle of making coffee. He was using a dripper and a filter.

‘Good timing,’ Yukawa said, pouring two cups.

‘I’m surprised. You’re not using your coffeemaker?’

‘That’s right. I thought I’d try being a coffee snob for a while. I even used mineral water,’ Yukawa said, holding out a cup.

‘Thanks.’ Utsumi accepted the drink and took a sip. One taste told her that he hadn’t upgraded his choice of grind.

‘Well? How is it?’ Yukawa asked.

‘Delicious.’

‘More delicious than usual?’

Utsumi hesitated a moment before saying, ‘Can I be frank?’

A despondent look came over Yukawa’s face and he turned back to his chair. ‘No need. I’m guessing your reaction is exactly the same as mine.’ He peered inside his coffee cup. ‘You know, a little bit ago, I used tap water to make the coffee. The results were exactly the same. Or at least, so similar I couldn’t tell the difference.’

‘I don’t think anyone could tell the difference, really.’

‘And yet it’s commonly agreed upon in culinary circles that water does make a difference to taste,’ Yukawa said, picking up a sheet of paper from his desk. ‘Water has a hardness, which is calculated by comparing total calcium ions and magnesium ions to the water’s calcium carbonate content. If the ratio’s low, the water is soft. A little higher means medium hardness. A lot higher and it’s hard water.’

‘I’ve heard of that.’

‘Apparently, soft water is best for most cooking. The point is the calcium content. If, for example, you use water that’s high in calcium when you cook rice, the calcium fuses with the rice fibres, and you end up with drier rice.’

Utsumi quirked an eyebrow. ‘Not good for making sushi.’

‘Conversely, if you’re trying to make a beef stock, hard water is preferable. The calcium fuses with the excess fluid in the meat and bones, making it rise to the surface so you can scoop it out. Something to remember the next time I do a consommé.’

‘You cook?’

‘Sometimes,’ Yukawa replied, setting the paper down.

Utsumi tried to picture the professor standing in his kitchen. An image popped into her mind – Yukawa with a wrinkled brow, hovering over a pot of soup, adjusting the water content and the strength of the flame as if it were some kind of science experiment.

‘So, any word?’ Yukawa asked.

‘Forensics got back to us. I have a report,’ Utsumi said, pulling a file out of her shoulder bag.

‘Let’s hear it.’ Yukawa sipped his coffee.

‘No arsenous acid was found in either the filter or the hose. However, they go on to note that even if there had been any poison in there, running a sufficient quantity of water through the filter would be enough to make any traces undetectable. The next part gets sticky,’ Utsumi said, taking a breath before continuing. ‘The filter and hose both showed a considerable buildup of undisturbed grime from long years of use, making it unlikely that either had been tampered with. Any recent removal of the filter or hose would have left some indication. There was some additional material: apparently, Forensics also checked beneath the sink for poison on the day of Mr Mashiba’s death. At the time, they moved the old detergent and containers that were sitting in front of the filter, and were able to confirm that only where those objects had been sitting was the dust beneath the sink disturbed.’

‘So not only the filter, but the entire area under the sink hadn’t been touched for some time?’

‘That’s what Forensics thinks, at least.’

‘Well, I agree with them.That was certainly the impression I got when I first looked under there. But, there is one other thing they should have checked on.’

‘I know what you’re going to say. Could poison have been inserted into the filter from the other direction – via the tap, right?’

‘That’s what inquiring minds want to know. Their answer?’

‘Though theoretically possible,’ Utsumi said, ‘realistically, it’s impossible.’

Yukawa took another sip of his coffee and frowned – not because the coffee was bitter, Utsumi guessed.

‘They tried your idea about using a long tube, like a stomach camera, inserting it into the tap end all the way up to the filter, then introducting the poison up through the tube, but they couldn’t get it to work. The problem was that the joint where the tap connects to the filter is practically a right angle, and they couldn’t get the tube to go around it. It might be possible if one were to use a specialized tool with a manipulable tip—’

‘That’s okay, you don’t have to go on,’ Yukawa said, scratching his head. ‘I don’t think our killer went to such technical extremes. Looks like I have to give up on the filter theory. Too bad; I had high hopes for that one. What we need now is another shift in approach. There has to be a blind spot somewhere.’

He poured the remaining coffee in the server into his own cup. A little spilled, and Utsumi heard the professor grind his teeth.

So he does get irritated, she thought. Such a simple question: where did the killer put that poison? And yet he can’t figure it out. None of us can.

‘What is our famous detective friend up to?’ Yukawa asked.

‘He’s gone to Mr Mashiba’s office to ask some more questions.’

‘Hmph.’

‘Did you hear something from him?’

Yukawa shook his head and took another sip. ‘I was with him the other day and we ran into Mrs Mashiba.’

‘So I heard.’

‘We talked a bit. She is a beautiful woman – enchanting, even.’

‘Were you helpless before her charms, Professor?’

‘I was merely reporting an objective observation. That, and I was a little worried about Kusanagi.’

‘Really? Did something happen?’

‘Not something happening, per se, just another obser -vation – one that requires the telling of a tale to be understood.

‘Once, back when we were in college, Kusanagi picked up these stray cats – kittens, actually, just born. They were both really weak, and anyone could see they weren’t long for this world. But he brought them up to his room anyway, and he skipped class to take care of them. He was using an eye-dropper to feed them milk. One of his friends asked him, “What’s the point? They’re just going to die anyway.” I remember his answer: “So what?” That’s all he said.’ Yukawa gazed off into the distance. ‘Kusanagi’s eyes when he looked at that woman were just like his eyes when he was taking care of those kittens. He knows something’s not quite right. And at the same time he’s saying to himself, “So what?”’