Salvation of a Saint

FOURTEEN

Steam poured from the mouth of the kettle. In sullen silence, Yukawa lifted it and emptied the boiling water into the sink. Then he took off the lid and, after removing his glasses so they wouldn’t fog, peeked inside.

‘How does it look?’ Utsumi asked.

Yukawa replaced the kettle on the burner and slowly shook his head. ‘No good. Exactly the same as last time.’

‘The gelatin?’

‘Still there.’

The physicist pulled up a metal folding chair and sat down. Linking his hands behind his head, he looked up at the ceiling. Instead of his white lab coat, he was sporting a black, short-sleeved T-shirt revealing slender but well-muscled arms.

Utsumi had come to visit him at the laboratory to watch him try to mix poison into the kettle using the trick he had come up with the other day. So far, the results were less than impressive. In order for the trick to work, he would have to use the kettle twice without melting the gelatin and allowing the poison to mix with the water. This required a thick layer of gelatin. But when he layered on a sufficient amount, the gelatin would fail to completely melt, leaving traces inside the kettle. Traces of the sort that had not been found by the Forensics investigation.

‘I guess it wasn’t gelatin,’ Yukawa said, scratching his head with both hands.

‘Forensics said the same thing,’ Utsumi said. ‘They were of the opinion that even if the gelatin melted completely, it would still leave a small amount on the inside of the kettle. Also, no traces of gelatin were found in the used coffee grounds. At least Forensics liked your idea, though. They tried several other materials.’

‘I’m guessing they tried wafers, then?’ Yukawa asked.

‘The ones for taking powdered medicine? Yes. Wafers leave a trace of flour in the grounds.’

‘Oh well, strike two,’ Yukawa said, giving his knees a slap and standing. ‘Unfortunately, it looks like we have to abandon this line of inquiry.’

‘It was a fantastic idea,’ Utsumi offered.

‘Even if all it accomplished was wiping that smirk off Detective Kusanagi’s face for a little while.’ Yukawa retrieved his lab coat from the back of the chair and put it on. ‘What’s the good detective up to, incidentally?’

‘Looking into Mr Mashiba’s past relationships.’

‘Ah, yes. Following through on his hunch, then. That might just turn out to be the best course to take, now that the kettle’s proved to be a dead end.’

‘Do you think some ex-lover killed Mr Mashiba?’

‘Lover or fighter, the most logical explanation remaining is that our killer waited until Ms Wakayama left on Sunday morning, entered the Mashiba residence by some means, and put poison in that kettle.’

‘So you’re giving up.’

‘I wouldn’t call it that. I would call it a consistent application of the process of elimination. Kusanagi may be smitten with Mrs Mashiba, but that doesn’t mean he’s blind to the basic facts. The direction he’s taking this investigation in makes a good deal of sense, if you ask me.’ Yukawa sat back down and crossed his legs. ‘The poison – arsenous acid, was it? Can’t you identify the killer by tracing sales records?’

‘That’s proving difficult. Producing and selling arsenous acid as a pesticide was, for the most part, stopped about fifty years ago, but it is still being used elsewhere for some rather surprising things.’

‘Such as?’

Utsumi opened her notepad. ‘Well, there’s pest control – that one’s pretty obvious. Then there’s wood treatments to prevent rotting, medicine used in dentistry, semiconductor manufacturing … that’s about it.’

‘Dentistry! Now that is surprising.’

‘They use it to kill nerve endings in the teeth. But the chemical is in a paste form, which is then dissolved in water, leaving only about a forty percent concentration of arsenous acid. It’s not likely to be the substance used in this case.’

‘So what is likely?’

‘An exterminator would have access to arsenous acid in sufficient concentrations. They use it to control termites, mainly. You have to write down your address and name whenever you purchase it, so we’re checking into that. Of course, merchants are only required to keep those records for five years, so if the poison was purchased before then, we’re out of luck. We’re equally out of luck if the killer obtained the arsenous acid illegally.’

‘I have a feeling our killer wouldn’t slip up in such an obvious way. I think you’d better wait to see what Detective Kusanagi turns up.’

‘I just don’t think our killer put the poison directly into the kettle.’

‘Why not?’ Yukawa raised an eyebrow. ‘Because the wife couldn’t have done it, then? You’re right to suspect her, but you can’t conduct your entire investigation based on an assumption like that.’

‘I’m not assuming anything. There’s just no evidence anyone else visited the Mashiba residence that day – none at all. Say for instance an old lover came by, like Detective Kusanagi is suggesting. Don’t you think that Mr Mashiba would have at least offered her a cup of coffee?’

‘Not everybody would. Especially if he didn’t welcome the visit.’

‘How would an unwelcome person get poison into the kettle, then? Wouldn’t Mr Mashiba have seen?’

‘They might’ve had a chance if, say, he had to go to the bathroom. If they hung around long enough that an opportunity presented itself.’

‘Not a very solid plan. What do you think they would have done if Mr Mashiba didn’t use the bathroom?’

‘They might’ve had a backup plan, or they might have been prepared to call the whole thing off if the right moment didn’t arise. There’s no risk to the killer that way.’

‘Professor Yukawa,’ Utsumi said, staring the physicist in the eyes. ‘Whose side are you on, anyway?’

‘If you must know, I’m on nobody’s side. I simply want to analyze the data, perform the necessary experiments, and come up with the most logical answer I can find. Currently, your side’s losing, that’s all.’

Utsumi bit her lip. ‘I’d like to amend my previous statement,’ she said. ‘In all honesty, I do suspect Mrs Mashiba. Even if she didn’t do it, at the very least, she was involved. Call me stubborn, but that’s what I believe.’

‘So that’s how it is, is it? I’m surprised.’ Yukawa chuckled. ‘What was the reason you suspect her, again? The champagne glasses? You thought it was odd that she hadn’t replaced them in the cupboard, as I recall.’

‘There were other reasons, too. The night of the murder, our department left a message on her phone. I asked the officer who called her, and he said that he left a message saying he had urgent news concerning her husband, and wanted her to call back. When she called around twelve o’clock that night, he explained the general facts of the case. At the time he didn’t mention there was a possibility Mr Mashiba was murdered.’

‘Hmm. And?’

‘The next day, Mrs Mashiba took the first flight back to Tokyo. Detective Kusanagi and I picked her up at the airport, and in the car, she called Hiromi Wakayama and told her, “I can’t imagine what you’ve been through”,’ Utsumi said, recalling the mood in the car. ‘That struck me as strange.’

‘Couldn’t imagine what she’d been through, huh?’ Yukawa muttered, tapping his knee lightly with one finger. ‘That would suggest the conversation in the car was the first she’d had with Ms Wakayama after hearing about the death.’

‘That’s what I thought. That’s exactly what I thought,’ Utsumi said, a smile slowly spreading across her face. ‘Mrs Mashiba left her house key with Hiromi Wakayama before leaving for Hokkaido. But she was already onto the relationship between her husband and Hiromi before leaving. If she’d heard that her husband died under unusual circumstances, don’t you think she would have tried to call Hiromi right away? Not only that, but she didn’t even call their friends, the Ikais. It just doesn’t make sense.’

‘And what is your deduction from all this, Detective Utsumi?’

‘I think she didn’t call Hiromi or the Ikais because she didn’t need to. She knew exactly why her husband had died, so why call to ask for details?’

Yukawa grinned and scratched his lip. ‘Have you shared this theory with anyone?’

‘I told Chief Inspector Mamiya.’

‘And not Kusanagi.’

‘Detective Kusanagi would just tell me to stop basing everything on “feelings”.’

Yukawa frowned and got up to walk over to the sink. ‘That kind of assumption will get you into trouble. I can’t believe I’m the one saying this, but Kusanagi’s quite a gifted detective. Even supposing he has feelings for a particular suspect, he’s not the kind to abandon reason. What you just told me wouldn’t necessarily change his mind on the spot, of course; he’d probably start off with a rebuttal, but he wouldn’t ignore you. And he would think about it. Even if the conclusions he comes up with aren’t the ones you want, he won’t turn a blind eye to evidence.’

‘You seem to trust him quite a lot.’

‘If I didn’t, I wouldn’t have helped with so many of his cases,’ Yukawa said, his lips parting in a white-toothed smile. He scooped some coffee into the coffeemaker.

‘What about you?’ Utsumi asked. ‘What do you think about my idea?’

‘It makes a lot of sense. I would expect someone who’d heard her husband had died to try to get all the information she could as soon as possible. It’s extremely odd that the wife didn’t try to contact anyone.’

‘I’m glad you agree.’

‘I am, however, a scientist,’ Yukawa continued. ‘If I’m presented with one theory that feels off for psychological reasons, and another theory that is physically impossible, though it might give me some pause, I’d have to choose the former. Of course, if there were some way to pull off a timed release of poison into the kettle other than the one I came up with, that would be a different matter.’ Yukawa poured tap water into the coffeemaker. ‘I wonder if coffee made with mineral water really tastes different.’

‘I understand it has less to do with taste than it does with health. Apparently, the wife occasionally used tap water when her husband wasn’t looking. I might’ve mentioned this, but Hiromi also admitted to using tap water when she made coffee on Sunday morning.’

‘So ultimately, the only one really using mineral water was the victim.’

‘Which is why we originally assumed the bottled water had been poisoned,’ Utsumi said.

‘But you had to abandon that idea when the lab results came up negative.’

‘Just because they didn’t find anything doesn’t mean there’s a zero percent chance the bottled water was poisoned. Some people wash out plastic bottles before recycling them. The lab admitted this could be the cause of the negative results.’

‘People wash out bottles of tea and juice, sure,’ Yukawa said. ‘But bottles of water?’

‘Habits are hard to break.’

‘Well, that’s true enough. But this would make our killer an extremely lucky person – to have the victim erase the evidence for them.’

‘Assuming the wife was the killer, that is,’ Utsumi said, glancing at Yukawa. ‘Unless you object to that kind of deductive reasoning?’

A wry smile came to Yukawa’s lips. ‘I don’t mind. We occasionally use hypotheses in my line of work … though most of them get thrown out pretty quickly. Is there some benefit to supposing that the wife was the killer?’

‘It was the wife who told us that Mr Mashiba only used bottled water. Detective Kusanagi thinks she wouldn’t have told us that if she poisoned the water, but I think exactly the opposite. If she assumed we would eventually find poison in one of the bottles, she might have told us in advance to deflect suspicion. But in the end, we didn’t find any poison. That left me confused, to be honest. If she was the killer and she did use some method to poison the water in the kettle, what reason could she possibly have for telling the police that Mr Mashiba only used bottled water? It got me thinking. Maybe she expected us to find poison in the empties?’

While Utsumi was talking, a grim look came over Yukawa’s face. He was staring at the steam coming from the coffeemaker. ‘Do you think she might not have expected her husband to wash the bottles after using them?’ he asked.

‘If I were she, I might not have. I would’ve expected them to find a bottle with poison in it on the scene. But Mr Mashiba used all of the poisoned water in the bottle when he made his coffee. Then, while he was waiting for the water to boil, he washed the bottle clean. And because she didn’t expect that, she tried to stay one step ahead of the police by suggesting that the killer had poisoned the bottled water. When you think of it that way, it all makes sense.’

Yukawa nodded, pushing his glasses up with the tip of his finger. ‘There is a certain logic to it.’

‘I understand there are a lot of problems with the theory, but nothing that keeps it from being a real possibility.’

‘I agree. Still, I wonder if there’s a way to prove your hypothesis.’

‘There isn’t, unfortunately,’ Utsumi said, chewing her lip.

Yukawa removed the pot from the coffeemaker. He poured the coffee into two mugs and offered one to Utsumi.

She thanked him and accepted the mug.

‘You two aren’t in cahoots, are you?’ Yukawa said abruptly.

‘Huh?’ Utsumi blinked.

‘You and Kusanagi. You aren’t working together to drag me into this, are you?’

‘What makes you think that?’

‘Because the two of you are doing such a good job at piquing my intellectual curiosity, even though I’d decided not to get involved in another police investigation. And you even threw in a tantalizing dash of spice to seal the deal: the prospect of seeing whether Kusanagi finds true love.’ Yukawa chuckled and sipped his coffee, savouring every drop.