After finding the little rhinoceros, Li Er went mad.

With the imperial edict issued, all the prefectures along the coast of the Tang Dynasty began to operate with unprecedented efficiency.

Under Li Shimin's strict orders and inspired by divine pronouncements, countless manpower and resources were mobilized to Dengzhou, Laizhou and other places.

The skilled craftsmen from the Ministry of Works, along with their apprentices, set up huge iron pots along the coast; the soldiers were organized to fetch water from the sea day and night and carry it into the pots, one load at a time.

A roaring flame burned at the bottom of the pot, and thick white steam shot into the sky, making the entire beach seem like a legendary alchemical retreat for immortals.

Everyone waited with immense excitement and reverence for the miracle to occur, for the pure white salt to emerge from the churning seawater.

However, three days later, when the first batch of sea salt was scraped out of the pot, everyone was dumbfounded.

There were no snow-white crystals, no purity as imagined.

What appeared before them was a pile of grayish-black powder mixed with sand and unidentified impurities. It smelled fishy and a pinch of it was so bitter that it made them gag instantly.

"What...what is this?"

The Vice Minister of Works, who was in charge of supervising the construction, turned pale.

"It's bitter...it's so bitter! This isn't salt, it's poison!"

"It was painful," said a skilled craftsman who had tasted it.

They refused to believe it, so they changed to cleaner pots, used filtering cloths, and even tried to burn black stones like the immortals, but the result was the same. Pot after pot of seawater was boiled dry, leaving only piles of bitter wasteland.

The news was rushed back to Chang'an, like a bucket of ice water poured over the heads of Li Shimin and his court officials.

The atmosphere inside the Taiji Hall was extremely oppressive.

The salt sample, delivered by express courier from Dengzhou, was placed in a wooden box on the dragon's desk.

It silently mocks everyone's ambitions.

"Why is this so?" Li Shimin's voice was low and filled with confusion. "I and my ministers witnessed the immortals taking something from the sea and sprinkling it with fine salt. Why is it that when we imitated them, we received this poison?"

"Your Majesty," Duan Lun, Minister of Works, stepped forward, his face covered in sweat, his voice trembling, "we are incompetent! We have exhausted all mortal wisdom, yet we cannot replicate even a fraction of the immortals' abilities. Perhaps... perhaps we have overlooked a crucial step in the immortal technique."

"Immortal techniques..." Li Shimin pondered these two words, a flash of understanding appearing in his eyes.

Yes, they are mortals, so how could they easily grasp the full scope of the immortal arts?

What the immortals show us may only be the result, while the real process is something that mortals cannot imagine out of thin air.

He figured it out. The direction was right, but they were missing the most crucial blueprint.

"Prepare the carriage!" Li Shimin abruptly stood up. "Set up the carriage at the Altar of Heaven! I want to... consult the Immortals again!"

Incense smoke wafted around the altar of Heaven.

This time, the offerings seemed rather meager.

There were no gold, silver, or jade artifacts, only a wooden box containing that failed, bitter "sea salt".

Beside it was a scroll of silk written by Li Shimin himself, which detailed their failed attempt to boil seawater for salt and their yearning for immortality.

This was less of a ritual and more of an honest self-examination of one's own incompetence.

At Li Shimin's command, the sacrificial offerings were set on fire.

……

At Jianghe's home, he was playing with building blocks with Xiao Sizi, trying to build a castle that was taller than yesterday's.

[Ding! New offering link detected. Accept?]

Jiang He was taken aback for a moment, then immediately chose "Yes".

In the center of the living room, a flash of light appeared, and a small clump of grayish-black powder and a roll of silk that was half-burned appeared out of thin air.

"What is this?" Jiang He walked forward curiously, picked up a little powder and smelled it; it had a familiar bitter and salty smell.

"Coarse salt? No, it's even worse than coarse salt; it's a mixture of brine and impurities."

He understood immediately.

Unfolding the scroll again, and looking at Li Shimin's words—a mixture of classical and vernacular Chinese, filled with respect and bewilderment—Jiang He finally understood.

These people... they actually just boiled it with seawater!

He could not laugh or cry.

It seems that without modern chemical knowledge, trying to deduce the process from a demonstration is simply a pipe dream.

Well, he'd been waiting for this opportunity anyway.

"System, extract the blueprints for primary salt production technology."

The drawings have been extracted and can be transmitted as a data stream or printed as a physical document.

"Physically, it's printed on a... well, the most ordinary A0 drawing paper."

The next second, a huge sheet of paper filled with various complex process flowcharts appeared in his hand.

This is the salt-making technology that combines the "sun-drying method" and the "boiling method" produced by the system.

Jiang He thought for a moment; he couldn't just send the modern blueprint over directly. He picked up a pen and, with his passable calligraphy, wrote four large characters next to the title of the blueprint:

The Exploitation of the Works of Nature: Chapter on Sea Salt

Then, he placed the blueprint where the offerings had appeared, and with a thought, decided to send it back.

The Great Tang Dynasty, the Altar of Heaven.

Under the tense gaze of Li Shimin and his ministers, a soft white light suddenly appeared from the pile of ashes of bitter salt and silk.

As the light faded, a huge roll of white fairy paper lay quietly in place.

A palace attendant stepped forward tremblingly, picked it up, and presented it to Li Shimin.

Li Shimin slowly unfolded it, and after just one glance, his breath caught in his throat!

Instead of lengthy texts, there were exquisite pictures that he had never seen before, yet seemed to be able to understand!

When Duan Lun, the Minister of Works, was summoned to the Emperor's presence, he was struck dumb at the mere glance he took, and then he was overjoyed!

"A miracle...a divine intervention!" He pointed at the blueprints, explaining incoherently, "Your Majesty, please look! This diagram...this diagram is the true secret of salt production!"

"The first step is to create a tidal flat! The immortal has drawn a plan to build tiered pools along the coast, allowing seawater to be exposed to the sun at each level and evaporate on its own! This method is unheard of!"

"The second step is sand filtration! The concentrated brine is filtered through a sand tank to remove impurities! Brilliant! It's a stroke of genius!"

"The third step, brine extraction! So that's why the salt we produce is bitter—because it contains highly toxic brine! This method from the immortal teaches us how to separate out this poison!"

"The final step is 'frying the salt in a pan'! After these steps, you'll get truly snow-white refined salt!"

With each step Duan Lun explained, the gasps of surprise from the courtiers grew louder.

After he finished explaining, the entire altar fell silent.

Everyone was completely captivated by the timeless wisdom contained in this blueprint.

This is not a simple enlightenment, this is hands-on teaching!

It's like slapping a complete, mature industrial process right in their faces!

Li Shimin stroked the copy of "Tiangong Kaiwu" with trembling hands, and murmured, "I understand... The immortal is not stingy with his teachings, but wants to see our sincerity and efforts first."

Although we were defeated, we proved our determination to build a strong nation, and therefore... the Immortal bestowed this supreme treasure upon us!

He raised his head, his eyes blazing with an unprecedented light, and proclaimed loudly, "Issue my decree! This drawing is to be designated a top state secret! The Ministry of Works shall immediately begin construction according to the drawing. Within a month, I demand to see refined salt as fine as snowflakes!"

Chang'an, West Market Teahouse

The political upheavals in the imperial court had not yet fully reached the common people.

But the people of Chang'an were sensing some unusual changes in their own ways.

In a teahouse in the West Market, a storyteller was recounting tales of a bygone era with great enthusiasm, but the listeners' attention was elsewhere.

"Hey, Old Wang, have you heard? The government has been recruiting people lately, saying they need to go to the sea in the east to salvage things," a foreign merchant said in a low voice to the cloth shopkeeper next to him.

The cloth merchant curled his lip: "More than that! My convoy of goods has been stopped several times on the official road. They're all soldiers transporting big iron pots and black stones, saying it's important military business, and they'll arrest anyone who dares to block the way!"

A down-on-his-luck scholar, drinking alone in silence, sneered, "What are you all? I heard that the current emperor saw immortals in heaven a few days ago!"

"Oh?" This immediately drew everyone's attention.

Seeing that he had become the center of attention, the scholar cleared his throat and said mysteriously, "It is said that a huge opening has appeared in the sky, called the Heavenly Curtain, where you can see the lives of the gods! And the gods are always accompanied by exquisitely beautiful fairy boys and girls!"

"Really?"

"You're just bragging!"

"Why would I lie to you?" the scholar exclaimed anxiously. "My cousin's younger brother works in the Imperial Guard, and he saw it with his own eyes that day! He even said that after the immortals ate something in heaven, His Majesty went crazy, ordering sheep to be raised and sending people to fish at the seaside... I think this salt-making project was probably also guided by the immortals!"

His words silenced the teahouse.

The people were skeptical, but the recent series of unusual actions by the imperial court seemed to confirm these fantastical rumors.