The math teacher was on the verge of asking his old friend what he had really come for when the sign for Benten-tei came into view. Another wave of unease washed over him. How would Yasuko react when she saw them? It was unusual under any circumstances for Ishigami to show up at this time of day, and if he came with a friend, she would be sure to suspect the worst. He just hoped she had the sense to act naturally.
Yukawa stepped up to the sliding glass door to Benten-tei, opened it, and went inside. Ishigami followed, somewhat hesitantly. He saw Yasuko behind the counter, in the middle of helping another customer.
“Welcome!” she said brightly to Yukawa. Then she turned to look at Ishigami. A look of bewilderment came into her eyes, and her smile froze on her face.
“Did my friend do something?” Yukawa asked.
“No—nothing,” Yasuko shook her head, still smiling uncomfortably. “He’s my neighbor. He always buys his lunch here…”
“So I’m told. I’m here on his recommendation.”
“Thank you, then,” Yasuko said, nodding politely.
“We were classmates back in university,” Yukawa went on, turning to Ishigami. “I was just over at his place the other day.”
“Oh, right.” Yasuko smiled and nodded again.
“Oh, he told you?”
“Yes, in passing.”
Yukawa nodded, smiling. “So, what do you recommend? No, what does he usually buy?”
“Mr. Ishigami almost always gets the special, but I’m afraid we’re sold out…”
“That’s too bad. Let’s see, then. They all look so good…”
While Yukawa selected a boxed lunch, Ishigami stood looking out through the sliding glass door. He wondered if the detectives were watching from somewhere nearby. If possible, he didn’t want them to see him being friendly with Yasuko.
Then another thought occurred to him, and he gave Yukawa a sidelong glance. Could Yukawa be trusted? Did he need to be on his guard around this old friend? If he’s friends with Kusanagi, anything he sees here might eventually wind up back with the police.
Yukawa had finally decided on a lunch box. Yasuko had just gone back with his order when the glass door slid open again and a man in a dark brown jacket stepped into the shop. Ishigami glanced behind him as casually as he could. He felt his jaw clench involuntarily.
It was the man he had seen dropping Yasuko off the other day in front of their apartment building. From beneath his umbrella, Ishigami had watched them talking together. He had gotten the impression that they were old friends—or something more.
The man didn’t seem to notice Ishigami. He was waiting for Yasuko to reappear. When she came back to the front and saw him, her eyes opened in surprise. The man merely nodded, smiling, with a look that said, We’ll talk after you’ve dealt with these customers.
Who is he? Ishigami wondered. When did he show up, and how did he get so close to Yasuko Hanaoka? Ishigami vividly remembered the look on Yasuko’s face when she had stepped out of the taxi the night before. He had never seen her looking so full of life. Her face hadn’t been the face of a mother or an employee at a lunch box shop. It had been her true face, he thought. A woman’s face.
A face she wore for this man, and would never wear for Ishigami—
Ishigami’s gaze darted between the mystery man and Yasuko. He thought he could feel the atmosphere shift between them. A feeling of anxiety clutched at the math teacher’s chest.
Yukawa’s lunch box was ready. He paid, took the bag, and turned to Ishigami. “Thanks for waiting.”
They left Benten-tei and went down to the Sumida River at the stairs by Kiyosu Bridge. They began to walk along the river.
“So who was that guy?” Yukawa asked.
“Huh?”
“The guy that came into the shop. It looked like you recognized him.”
Internally, Ishigami cursed his old friend’s powers of observation. “Really? Can’t say that I did,” he replied, striving to maintain his composure.
“Oh, well, never mind then.” Yukawa said.
“So what is the urgent business all about, anyway? Don’t tell me you came all this way just to buy a lunch box?”
“Oh, right. I hadn’t gotten to why I came, had I?” Yukawa frowned. “Like I said before, that Detective Kusanagi has a habit of bringing me all of his annoying loose ends. Anyway, this time he came because he found out I knew you, and you’re her neighbor. It turns out he has a … well, a rather unpleasant request.”
“What’s that?”
“To put it bluntly, the police are still investigating the murder of your neighbor’s ex-husband, and they have suspicions about your neighbor. Unfortunately, they haven’t got a shred of evidence linking her to the crime. So, they’d like to keep tabs on her, watch what she does—you know, observe. But there are limits to how far they can take that. Which is where we come to you.”
“Wait, they don’t want me to watch her for them, do they?”
Yukawa scratched the back of his head sheepishly. “Er, well, yes, actually they do. It’s not like they want you to observe her all the time, twenty-four seven. They just want you to keep an eye on the place next door, and let them know if you notice anything. I know, it’s a serious imposition, but that’s how they are.”
“So that’s why you came out here to talk to me?”
“Well, I expect the police will make a more formal request soon enough. They just wanted me to feel you out about it first. Personally, I wouldn’t care if you said no—in fact, I almost think you should, but I thought I owed my detective friend at least a preliminary chat with you.”
Yukawa looked sincerely put upon. Secretly, though, Ishigami wondered if the story was really true. Would the police really go to a civilian with a request like that?
“Is that why you wanted to go to Benten-tei, too?”
“Honestly, yes. I wanted to see this suspect for myself. And I gotta say, now that I have, I don’t think she’s capable of killing someone.”
Ishigami was about to tell him that he agreed, but he held back. Instead, he said, “Well, they say you shouldn’t judge a book by its cover.”
“True enough. So, what do you say? How would you answer if the police asked you to spy for them?”
Ishigami shook his head. “Honestly, I’d rather not get involved. I’m not in the habit of prying into other people’s lives, and besides, I barely have the time. It might not look it, but I’m rather a busy man.”
“So I thought. Look, I’ll just tell Kusanagi what you said. That should put an end to the whole idea. Sorry if I made you uncomfortable at all.”
“No, not a bit.”
They were approaching Shin-Ohashi Bridge. They could already see the homeless people’s shanties along the riverside.
“So the murder happened on March tenth, I think he said,” Yukawa said. “Kusanagi mentioned you came home kind of early that day?”
“Yeah. I didn’t have anything scheduled that night. I think I got back around seven—I believe that’s what I told him.”
“After which you holed up in your room, doing battle with those mathematical problems of yours?”
“Something like that.”
As he talked, Ishigami wondered if Yukawa was actually trying to see if he had an alibi. If that was the case, then he already suspected Ishigami of being involved.
“Which reminds me, I have no idea if you have any other hobbies. I mean something other than math.”
Ishigami snorted. “Hobbies? Not really. Math is about all I do.”
“What you do to blow off steam, then? Do you like going for drives?” Yukawa pantomimed gripping a steering wheel.