"You're not quite right about that," Cheng Ying said with a smile. "Business is all about mutual consent. Since kerosene is more practical than candles, it's only natural for my kerosene to sell."
On the Douluo Continent, while soul masters possessed all kinds of fantastical abilities, the development of technology was still stuck at a medieval level. To a noble like Ye, a kerosene lamp was practically a miracle especially its adjustable brightness, which intrigued him greatly.
"But what I'm really interested in is your kerosene," Ye said. "As for the lamp, it won't make much profit."
"That's going to be a problem," Cheng Ying replied. "The technology for refining kerosene is connected to many more advanced techniques. If you had, say, tens of millions of gold soul coins, I might be willing to sell it to you. But not many people could afford such a price, and just the kerosene itself isn't worth that much."
"If you only want the lamp technology, though, I'll sell it for 100,000 gold soul coins. If you can't manufacture the glass covers, you can outsource them to my glassworks—I guarantee a price 30% lower than the market."
In this era, glass was considered a luxury, even an art form. Yet in Cheng Ying's store, it was a mere household item. Even at 30% less, he'd still be making a tidy profit.
"You really want to drink the soup and lick the bowl clean," Ye chuckled. Still, Cheng Ying could see the interest in his eyes, so he continued:
"This is an honest price—we both profit. The kerosene lamp is just an appetizer. Take a look at all the other things on my shelves. Who's to say we won't have more chances to work together in the future?"
"How about this—if you still feel it's a raw deal, I'll throw in a free trick. Didn't you just say candles need trimming? I've got a method that doesn't require trimming at all."
Turning his head, Cheng Ying called out, "Bo! Bring me one of my candles."
Du Gu Bo quickly went to the desk and brought back a candle. In just a few days of following Cheng Ying, he had come to truly admire his teacher. Though Cheng Ying claimed he was only teaching him the most basic concepts, Du Gu Bo could clearly tell—it was precisely the fundamentals that were most powerful. Whether it was the theory of cells or the atomic model, all of it had been deeply enlightening. His respect for Cheng Ying had only grown.
Cheng Ying took the candle and lit it in front of Ye. To Ye's amazement, as it burned, the wick naturally separated into three strands, which then burned into ash. Simply twisting the wick into a three-strand braid eliminated the need for trimming altogether.
The principle was simple, but before seeing it with their own eyes, no one would've thought of it.
"As you can see, it's really that simple. I call the power of this kind of change 'technology.' Everything I sell is something new that can improve everyday life," Cheng Ying said, extinguishing the flame and gesturing toward the other goods on display.
Ye finally understood—what Cheng Ying was selling wasn't just individual items, but rather the ideas and innovations behind them. What he called "technology."
"Well, since I've already accepted your gift, it would be petty of me not to buy anything. I'll have someone send over the 100,000 gold soul coins soon. So, where's the blueprint?"
At those words, Cheng Ying pulled a sheet of paper from behind the counter. With clean, measured strokes, he quickly sketched a full three-view diagram of every component of the kerosene lamp, complete with a scale and clear structure.
He wasn't worried Ye would renege—after all, the kerosene lamp was just one of many ideas in his mind. If it helped him get a read on someone's character, he had no regrets.
"This method of drawing is quite interesting. It's my first time seeing something like this, yet I can understand it at a glance. Much easier to follow than those confusing blueprints the craftsmen use. Is this also part of your 'technology'?"
"Sort of," Cheng Ying said. "Three-view diagrams are just the basics of drafting." He couldn't help but feel a bit of trauma at the memory of his university engineering drawing classes.
"I hope we'll have more opportunities to work together in the future," Ye said, offering his hand.
"I still have a few store treasures I haven't sold yet," Cheng Ying replied with a grin, shaking his hand.
"If they're store treasures, I'm sure they're valuable. By the way, I never got your name."
"Cheng Ying."
"Then farewell for now, Brother Cheng." Ye rolled up the blueprint, said a few words to his servant outside, and departed.
That very afternoon, a carriage arrived at the little shop loaded with 100,000 gold soul coins. Ice Empress, who had been eagerly awaiting the arrival of this fortune, squealed with excitement and dove into the shimmering pile of gold.
"Mine! All mine!"
But before she could truly enjoy rolling in wealth, Cheng Ying scooped her up by the armpits. "How many times do I have to tell you? Don't play with money. Everyone touches that stuff—it's filthy."
"You're not my dad! What's yours is mine anyway! I'll play if I want!" Ice Empress struggled, her arms flailing—but given her short stature, she was entirely helpless once lifted off the ground. Without revealing her strength, she couldn't break free at all.
"Gold coins, huh? Honestly, they're no big deal," Cheng Ying said. "Soon enough, you'll see—a stack of paper, even a string of numbers, can get you more excited than this."
He had noticed something important: there wasn't a complete banking system on the Douluo Continent yet. That was a huge opportunity.
"Are you kidding? Paper will never be better than gold coins! I don't believe it!" Ice Empress pouted as she watched Du Gu Bo haul a large chest of coins into the shop.
Cheng Ying patted her head with a mysterious smile. "You'll understand eventually. When that day comes, I guarantee a string of zeros will make you smile from ear to ear."
With that, he carried her back inside. The servant who delivered the money didn't think much of it—just another spoiled little girl from a noble family.
"Hey, Xiao Ying," Ice Empress said as she licked a strawberry-flavored ice pop. "Are you really doing all this weird stuff just to make money?"
"Not entirely," Cheng Ying said, lifting her onto his lap like a plush pillow.
"It's mostly about living more comfortably. Just like that ice pop you're eating—there are so many wonderful things in life that haven't appeared in this world yet. If I want to enjoy them, I have to make them myself."
"We have ten thousand years—that's more than a hundred lifetimes for ordinary people. Wouldn't it be a waste to spend it just drifting through?"
"Think about it. If you had to go back to a time with no ice cream, no stir-fried food, no stories, no lanterns—would you want to?"
Ice Empress imagined such a dull life and immediately shook her head. "No way. That sounds boring. I don't even want to return to the Extreme North anymore."
"Exactly! That's my goal." Cheng Ying grinned slyly. "Now, how about a story?"
Ice Empress, who insisted on hearing a story every day, nodded eagerly, curious what he would tell her this time.