My cultivation disguise has been exposed by Xiao Sizi.

Li Chen clapped his hands like a hands-off manager.

"The master leads you through the door, but the practice is up to you. I've taught you the principles, but as for the specific proportions, experimental materials, and how to turn the blueprints into reality..."

Li Chen patted Li Tai on the shoulder and said earnestly, "This requires you, a genius of your generation, to personally explore and experiment step by step! Don't be afraid of failure; science is born from countless failures!"

"Rest assured, Master! Qingque will never let you down!"

Li Tai rushed to the mountain of books as if he had found a treasure, tightly hugging several thick picture books. His protectiveness of his food was even more frantic than when he protected the position of crown prince.

"Alright, that abandoned courtyard on the east side will be your private laboratory from now on. Use all the materials in the palace as you like, and if you need more, I'll have someone 'restock' them from outside."

Li Chen yawned, turned around and left the courtyard with a smug look on his face.

……

Noon the next day.

Li Shimin and Empress Zhangsun were worried about their second son, who had been left in the Prince of Qin's residence, so they brought a large amount of gifts and visited him again.

"Chen'er, has Qingque caused you any trouble these past few days? His stubborn nature..." Empress Zhangsun asked with some concern as soon as she entered the room, holding Li Chen's hand.

"Troublesome? He's not troublesome at all now."

Li Chen smiled and pointed towards the east wing, "If Mother is worried, she can go and see for herself."

Li Shimin snorted coldly, put his hands behind his back, and strode towards the east side courtyard, with Empress Zhangsun and Li Chen following closely behind.

As soon as I stepped into the gate of the east wing.

"Bang!"

A muffled thud, neither too loud nor too soft, came from the courtyard, followed by a plume of pungent black smoke rising into the sky.

The emperor and empress were startled and quickly covered their mouths and noses to look closely.

In the center of the courtyard, dozens of iron pots and glass jars of various sizes were laid out.

And within the black smoke.

A fat man with a face covered in soot, a large patch of his hair singed, and clothes riddled with holes was holding a blackened tin can and dancing wildly in the yard like a madman, laughing loudly.

"Hahaha! It's done! It's done!"

"Blue...Blue Sparrow?!"

Empress Zhangsun looked at the fat man who was acting like a savage and was so heartbroken that tears almost fell from her eyes. She rushed over to him.

"My son! What's wrong with you? Have you suffered some kind of shock and gone mad?"

"Mother! Your Majesty! I am not insane! I am perfectly lucid!"

Upon seeing his mother, Li Tai excitedly held up a sheet of paper covered with geometric figures and chemical formulas. "Look, Mother! Given time, I can build an iron cart that doesn't need oxen! I will be remembered for eternity, even more famous than my father!"

Upon hearing this...

Li Shimin, who had initially felt a little sorry for Li Shimin, suddenly turned pale and let out a cold snort.

"You unfilial son! You spout nonsense! How dare you claim your fame surpasses mine? Utterly audacious!"

However, seeing Li Tai so wholeheartedly devoted to his "extraordinary skills," with no trace of the dark, power-hungry look in his eyes, Li Shimin, though cursing him, couldn't help but breathe a long sigh of relief.

As long as this kid stops coveting the throne and stops killing his brothers, Li Shimin will let him do whatever he wants, even if he goes off to make iron carts or plays in the mud in the yard every day!

"Father and Mother, don't worry. Qingque has found the true meaning of life."

Li Chen smiled and explained the so-called "the way of investigating things," leaving the Emperor and Empress stunned.

"Good! Good! As long as he walks the right path, it doesn't matter what he learns!" Empress Zhangsun looked at Li Chen with tears of gratitude. "Chen'er, it's all thanks to you! You not only saved your elder brother, but also saved Qingque!"

"Your Majesty, you flatter me. This is all I should do," Li Chen said, accepting the praise without any shame.

Seeing Li Tai so engrossed in the experiment, Li Chen was overjoyed.

"Thank me? I should thank that unlucky bastard Li Tai!"

He smugly calculated in his heart: "Now I have thugs, medicine makers, and even tools for weapon forging and scientific research! In the future, all I need to do is bask in the sun and drink tea in the courtyard, and a lot of cultivation points and scientific achievements will automatically come to me."

"Perfect! A huge thumbs up for this Immortal's ingenuity!"

In order to quickly monetize and promote Li Tai's research results.

After the Emperor and Empress left, Li Chen immediately sent someone to summon Cui Wanqing, the eldest daughter of the Cui family of Qinghe.

In the backyard.

Cui Wanqing looked at the several sheets of paper that Li Chen had left on the table: "Improved Drawings of the Curved Plow", "Structural Diagram of Movable Type Printing", and "Crude Soap Purification Process".

This exceptionally intelligent eldest daughter of a prominent family trembled violently with excitement, her breath catching in her throat!

"Immortal Master... these... these divine objects, from now on, will all be exclusively produced and sold by my Qinghe Cui Clan?!" Cui Wanqing asked incredulously.

"certainly."

Li Chen leaned back in his rattan chair, smiling as he said, "You provide the capital and the workshops, I'll provide the technology. I'll take 70% of the profits. With these revolutionary, game-changing products, the outdated workshops and industries owned by other aristocratic families will soon be completely eliminated, turning into piles of scrap metal!"

"You, the Cui clan of Qinghe, just wait to rise to prominence and become the foremost family in the Tang Dynasty!"

"Thank you so much, Immortal Master, for bestowing upon me this unparalleled opportunity! I, Wanqing, will give my all, even unto death!" Cui Wanqing knelt on the ground, kowtowing repeatedly.

She could already foresee how tragically those aristocratic families who still dared to oppose the Prince of Qin's mansion would wail in the torrent of history in the near future.

It was evening.

Li Chen lay alone on a rocking chair in the courtyard.

He closed his eyes slightly, sensing the subtle yet perceptible spiritual energy in the surrounding air that was slowly becoming richer.

With his appearance and the spread of these technologies and cultivation knowledge, the national fortune of the Tang Dynasty is rising at an alarming rate, and the revival of spiritual energy in this world is also accelerating.

"However... this concentration of spiritual energy is still too thin for me."

Li Chen felt the golden core essence within his body, which was like a vast ocean.

To continue breaking through, the required spiritual energy is enormous. It's like throwing a blue whale into a small ditch; the current amount of spiritual energy isn't even enough for it to take a couple of breaths. If it forces itself to cultivate, it might even completely drain the spiritual energy around Chang'an City, triggering a natural disaster.

"It seems I can't recklessly try to improve my cultivation level anytime soon."

Li Chen sighed helplessly.

"We can only patiently wait for this world to develop on its own for a while."

"Fine, I'll just treat it as a long vacation, enjoy the prosperity of the Tang Dynasty, and be a carefree salted fish prince!"