"What is this?" Andrea asked, chewing on dried fish.

The prince of Graycastle was tinkering with newfangled gadgets again. He was piecing together sections of copper pipes, then having Anna melt the joints, and finally having Soraya wrap them with a layer of soft magic creations. At first glance, it looked like the plumbing installed in bathrooms, only much larger. Each pipe was nearly as thick as her thigh, and without Hummingbird's weight reduction, one person couldn't even lift it.

Moreover, the copper pipes weren't just in one or two rooms, but ran horizontally throughout the entire castle and witch building. They entered from a corner of each room, ran along the base of the wall to a strange metal vent, then passed into the next room, only connecting to vertical pipes at the end.

This massive project attracted many witches to watch. Both Sleeping Island and the Witch Union showed great curiosity about it.

"Why don't you all guess?" he said with a mysterious smile. "If you guess right, I'll add an extra serving of ice cream bread to dinner."

Andrea was immediately intrigued. Ice cream bread! It was the most magical delicacy here, two pieces of bread baked until golden brown and crispy on the outside, sandwiched with a layer of sweet ice cream filling, something she hadn't even heard of in the Kingdom of Dawn. The first time she tasted it, she instantly fell in love with the food. Even though Ashes repeatedly mocked her, she would blush and eat it anyway, otherwise just looking at it on the plate was a kind of torment.

"Is this to run water into the rooms?" Ashes frowned.

Still short-sighted remarks, Andrea thought to herself, copper isn't a cheap metal. Since the small pipes in the bathroom can carry water, why make them so big?

However, given that recently, as soon as she opened her mouth to refute, she would be blocked by Ashes with a "Who said food is best when it's original?" which was also mentioned in front of Tilly, it was really inconvenient to deny it shamelessly, so she pretended not to hear the other party's superficial words.

"Short-sighted, it doesn't need such big pipes to run water," someone said from behind. "His Highness wouldn't do such a thankless thing."

Brilliant! Exactly what she thought. Andrea perked up. Besides herself, the only one who dared to speak to a transcendent witch in such a tone was Nightingale xiaojie from the Witch Union. She turned her head and saw her looking at Ashes with disdain, her chin raised at just the right angle.

That's how nobles should look!

Andrea praised secretly. After coming to Border Town, the witch she felt closest to was this elusive woman. Nightingale's skills displayed during the rescue of the relic witches were indeed extraordinary, and she was also of noble birth like herself, and even their hair color was very similar! In several sniper battles against mixed breed demonic beasts on the city wall, the other party also recognized her ability and shared dried fish with her, showing a noble demeanor.

Most importantly, she also disliked Ashes very much.

Although she didn't know how Ashes had offended her the first time she came to Border Town, but... the enemy of my enemy is my friend, isn't it? What's more, her personality is so compatible with her own.

"You talk like you know the answer," Ashes shrugged.

"Of course I know," Nightingale curled her lips. "I've been in the office ever since His Highness started drawing the design. I've seen all the drawings he made."

"That's not fair!" Mystery Moon mumbled.

"She's not participating in the guessing game," the prince's words made Nightingale's smug expression stiffen. "Here's a hint, these pipes are just part of a system. You might want to look around other places, it'll be easier to guess the answer."

"Goo!" Maggie and Lightning immediately flew out of the room, and the other witches didn't want to be left behind, so they scattered in all directions, following the direction of the pipes. Andrea deliberately lagged behind everyone, and after they left, she winked at Nightingale and called her outside the door.

"What is this exactly?" Andrea asked in a low voice. "If I guess right, I'll share half of my dinner bread with you."

"I don't know either." Nightingale's answer surprised her slightly.

"Didn't you say you saw all the drawings?"

"Yes, it's like *Fundamentals of Natural Science*, you recognize all the words on it, right? But can you understand what it means when they're put together?"

"Uh—" Andrea opened her mouth, but found that the other party was completely right. She had also flipped through that book herself, and it was indeed no different from the heavens.

"If you could understand His Highness's intentions just by looking at the drawings, I'm afraid only Anna in the Witch Union has such an ability," Nightingale suggested. "If you ask her, she can definitely tell you the answer."

After she left, Andrea hesitated again and again, but ultimately didn't call Anna out of the room. It wasn't out of coyness or embarrassment, but... reverence. She had never been afraid of vicious thugs or ruthless Judgment Army soldiers, but she felt a sincere fear of this girl who was not yet twenty years old.

She remembered once accidentally passing by the prince's office and hearing Anna talking to His Highness, the content of which made her goosebumps stand up all over her body even now. Things like high launch angle calculations, incorporating impact point parameters to correct the trajectory, and the conversion of dynamic potential energy in an ideal state left her rooted to the spot. Why, as a witch, could the other party say things she couldn't understand at all so fluently? From that moment on, Andrea developed a sense of admiration for Anna, feeling that she was not the same kind of person as herself at all, but at the same level as Tilly.

Since she couldn't get the answer by asking, she could only rely on herself. According to the prince's hint, Andrea investigated the rooms one by one—she found that in the completed rooms, the copper pipes were also separated by a right-angled iron fence, as if afraid that people would touch the pipes. If it weren't for barbarians like Ashes, it wouldn't matter if the copper pipes were touched, right? Thinking of Nightingale's words, "His Highness never does thankless things," it seemed that these iron fences clearly had their own purpose.

When she came to the first floor of the witch building, she had a new discovery. There was a flat house between the castle and the witch building, and the copper pipes leading to the two buildings extended from here.

Inside the house was a huge iron box, the lower half of the box was hollow, and the top had a large chimney... it looked a lot like a stove for cooking. And she saw that a pipe was directly connected to the well in the yard, like a water tower's water supply device.

Wait... could this be used to heat water?

But if the pipes were used to transport hot water, there was no need to make them so big, right?

Andrea couldn't figure it out, and in the end, she couldn't understand it.

Before dinner, His Highness gathered all the witches in the hall and said with a smile, "From today onwards, the castle's heating system is officially in operation."

"Heating?" Ashes asked in confusion.

"That's right, after the hot water is boiled in the boiler, the high-temperature steam enters the rooms along the pipes, increasing the temperature inside the rooms through radiators. As long as you close the doors and windows, you can quickly make the entire room warm," the prince explained. "Compared to fire buckets, which are inconvenient to move and require opening windows to release air, otherwise there is a risk of carbon monoxide poisoning, the new heating equipment has no such worries. You can enjoy spring-like warmth even when you sleep. After the debugging is completed, such heating equipment will gradually be popularized in residential areas."

"Then next, the ice cream bread winner for tonight, in addition to Anna, Soraya, and Hummingbird, who participated in the installation of the heating system, there is only one who guessed correctly, and that is—Tilly!"

At dinner, Andrea stared eagerly at Tilly enjoying the delicious smiling face, completely forgetting her nobility.