I drove to a familiar beef bowl restaurant. Takaoka-san followed with her own car.

　"Is this really what you want?" She was surprised, but when I told her that I wanted to eat here today, she seemed to agree.

　When I looked at her in a brightly lit place, I found her to be an extraordinary beauty. She was wearing an elegant pants suit with a body that looked like it was in good style. To say the least, she stood out from the crowd at the beef bowl restaurant.

However, she seemed to have not a bit of embarrassment. Moreover, she ate a set meal with a smile on her face, saying, "I'm really happy to get here because this is a place hard to come for woman alone."

　She may have a surprisingly good personality. No, no, no, wait. It's forbidden to be seduced by her. She is a stalker candidate. Besides, I never believe any woman.......

"So why are you so obsessed with me?"

　I threw a straight shot right down the middle.

She said, "That's a given. It's because Nagasaka-san helped me. At the time, I really couldn't help myself. so I really wanted to meet you again and thank you."

"Then you completed your mission." I said, "I guess this is the last time to meet each other."

"Yes, actually, but ...... there is one more thing I wanted to discuss with you......" She said.

"Ah? What?"

　I guess I looked quite uncomfortable. She bent her head apologetically and said,

"I'm sorry! If it bothers you, I never talk to you......"

　Her face looked very sad. It drove me to say,

"Okay, What's the matter?"

　Oh, no.

　I'ｍ dead. Well, that's not a first time. My nature that I can hardly say no when I'm asked to do something by people often led me to a critical situation.

　---

　Takaoka-san's consultation was a trivial manner. Her laptop was acting up. When she was using it, it suddenly turned off. She said that without it, she would be stuck at work even if she wanted to send it in for repair. I had an idea what was wrong, so I took a look at it and sure enough.

　The cooling fan was dead, and the CPU was overheating. I told her to buy a fan to put under the laptop.

"You are indeed an expert!　Thank you!　You've saved me again!" Takaoka-san said happily.

"Not at all," I said. "I don't need you to thank me anymore."

"No, please let me give thanks again someday. By the way, I was wondering that lately my laptop was unusually warm. Now I got the reason. But, to tell the truth, I was saved by that heat this time of the year."

"Heat is a terrible thing for me." I answered.

"What?"

"Do you know? Heat is the goal of all energy. Oil, electricity, nuclear power, etc...... all these energies end up as heat. That process is irreversible. You can't get anything out of heat."

　Right. I'm always having a tough time getting heat out of my systems. I must think about air conditioning and layout when I deliver the system to the client. Heat is my enemy. It's not so bad in the winter but in the summer, I'm always dreading when the system will shut down.

　Anyway, I don't think she'd understand me, and also, I'm sure she'd probably put off by what I said.

　However, she said with smile,

"The second law of thermodynamics."

"......!?"

　I involuntarily looked up at Takaoka-san's face. Her eyes were shining.

"It is also known as the "Law of Increasing Entropy". But you see, Nagasaka-san, it is not accurate to say that nothing can be taken out of heat. In fact, it is no exaggeration to say that almost all of the energy of modern civilization is derived from heat. Internal combustion engines, thermal power generation, nuclear power generation, and of course geothermal power generation ...... It is the fact that the energy can be extracted from heat to some extent, as long as there is a temperature difference, even if it is only a slight feeling of warmth. But, as you said, the entropy maximum is the state where the temperature difference has completely disappeared, from which nothing can be extracted."

　"......."

I lost for words for a while.

That was it. She was a general contractor for an energy company.......

　From there it was her turn all the way. No, once I tried to fight back.

"Well, heat has nothing to do with hydroelectric or wind power, does it?"

Her answer is following:

"The circulation of the earth's water and atmosphere, on which such power generation is based, was ...... originally caused by the sun's heat, wasn't it?"

　......It was a brilliant comeback.

　But strangely enough, I didn't feel bad. Once she asked, "Have you ever heard of the Seebeck effect?" I responded, "Oh, it's the reverse process of the operation of a Peltier element, isn't it?" "That's it!" Her eyes lit up again. I cannot properly express, but at least the tempo of the conversation with her is pleasant for me.

　When I noticed it, the clock had already struck 23:00.

　---