Li Shimin returned from inspecting the results of the Directorate of Works in high spirits.
Hou Junji, returning to Chang'an, was filled with confusion instead.
After the first month of the year, Hou Junji had been dispatched by imperial order to Hexi, tasked with overseeing the collection and consolidation of military intelligence.
Back when Tang was first founded, Hexi had been occupied by Li Gui. His regime had been destroyed for over ten years now. Since then, there had been no major wars—but minor conflicts were constant.
Tuyuhun would occasionally raid the borders. The Dangxiang people, long at odds with Tuyuhun, chose to acknowledge the Son of Heaven's authority and expressed willingness to help eliminate this great enemy.
Beyond the Hexi Corridor lay the Western Regions, where the situation was even more complex. Western Turkic pressure loomed over all the oasis states. Gaochang, the Ashina Mina tribe, Kucha, Khotan, and Shule all paid tribute to Tang on one hand, yet dared not offend the Turks on the other. This required Hou Junji to think carefully and deploy his spies with precision.
In mid-April, while in Lufu County, Hou Junji encountered a group he had not expected.
"Master Xuanzang… Wang Xuance?"
Lufu County took its name from the Lufu River. It was said that when the Champion Marquis defeated the Xiongnu, he poured fine wine into this river and drank with his soldiers. Thus, in the Former Han, the commandery was named Jiuquan.
The name, however, was awkward to pronounce. In a memorial he had already drafted, Hou Junji suggested that the emperor simply rename the city Jiuquan outright—aligning with later usage, commemorating the Champion Marquis's achievements, and signaling Great Tang's determination to unify the Western Regions.
From Lufu County, westward lay Yumenguan and Dunhuang; northward lay Xihai and Juyan Marsh. It was a natural crossroads for traffic in all directions.
Hou Junji stayed here both to gather intelligence and to allow his agents to easily blend into passing merchant caravans.
That day, however, the county magistrate came to report:
"A group arriving from Chang'an is here, holding an imperial exit pass."
"Does the general wish to inspect it?"
The Heavenly Khan's writ was not something anyone dared forge. But Hou Junji was both a duke of the realm and Right Guard General-in-Chief—his status was exceptional.
Moreover, since the group had also come from Chang'an, it was proper to inform him either way.
Travelers from Chang'an were nothing unusual. But travelers carrying an imperial exit pass…
Hou Junji immediately thought of someone.
"Is there a monk among them?"
When the magistrate confirmed there was—and that the leaders were named Xuanzang and Wang Xuance—Hou Junji's interest was instantly piqued.
Meet them. He had to.
Yet once they met, Hou Junji was disappointed.
Xuanzang looked utterly ordinary. Even after Hou Junji announced his titles as Duke of Lu and Right Guard General, the monk remained indifferent, barely engaging at all. Hou Junji was deflated.
The script he had already written in his mind—
The eminent monk offers praise, the duke humbles himself to befriend him, the two converse joyfully and leave behind a fine story for posterity—
had to be crumpled up and tossed aside. Hou Junji turned his attention instead to the other man.
"Xuance," he asked abruptly, "have you seen the marvel in the Ganlu Hall?"
The question seemed sudden, but Wang Xuance understood immediately.
He felt a twinge of difficulty, but ultimately nodded honestly.
"At the beginning of April, I saw it with His Majesty and the various dukes."
Hou Junji understood at once. Unconsciously, he felt closer to the man and pressed further.
"Was I mentioned?"
Oh, very much so.
Wang Xuance nodded truthfully.
Hou Junji's expression lit up.
"And when they spoke of me, what did that person say?"
"That person," of course, referred to a later descendant.
Wang Xuance felt even more uncomfortable. He recalled the emperor's warning, the Light Screen's casual use of "Old Hou" when mentioning this general, and that earthshaking yet ultimately abortive affair.
In the end, he chose to tell part of the truth.
"When that person spoke of the General, there was a sense of closeness."
"What the General accomplished is rare, even across all ages."
Hou Junji listened intently, then gave a look that clearly said:
That's it?
I destroyed kingdoms, propped up the flourishing Tang—surely you should say something like glorious merits to last a thousand years?
But Wang Xuance felt he had already done his best.
Thus, the two men—along with eighteen imperial guards—felt perfectly justified in eating a lavish meal at Hou Junji's expense.
Perhaps in repayment for that meal, Xuanzang finally spoke to Hou Junji of his own accord.
"General," he said calmly, "I only hope you will take good care of yourself."
After eating and drinking their fill, the group set off leisurely toward Yumenguan.
Hou Junji was left standing there, utterly baffled.
That strange monk—he really should learn from the monks in Chang'an how to offer blessings.
And that Wang Xuance—just because he has the merit of destroying a state, he thinks he can stand on equal footing with me? Not a single flattering word!
Watching them depart, Hou Junji snorted inwardly.
Hmph. This time, I won't just destroy Gaochang. I'll wipe out at least two more states!
But destroying a single state and acting so youthful and brash?
The matter was soon pushed aside.
The road to Tianzhu was long, and Xuanzang likely carried further imperial instructions. Who knew how many years it would be before Wang Xuance returned? By then, Hou Junji would not know how many merits he himself had accumulated.
By mid-May, most of his agents had been deployed, and preliminary intelligence from Hexi and the Western Regions had taken shape.
Hou Junji then began his uneventful journey back to the capital.
The destruction of the Eastern Turks the previous year had been momentous, and only now were its aftershocks becoming apparent.
All the counties of Hexi celebrated openly. When they looked at the Dangxiang tribes and the Jie Hu tribes nearby, their gazes grew far less courteous.
The Hu tribes, however, refused to back down.
What are you so proud of? That's not just your emperor—he's our Heavenly Khan too!
The states of the Western Regions became much more compliant. The northern tribes weighed their options and decided to compete with Xueyantuo for the scraps left behind by Tang's annihilation of the Turks.
For a time, Hexi became unusually peaceful.
Then Hou Junji frowned.
Except for that one death-wish of a state: Tuyuhun.
This time in Chang'an, he would definitely urge His Majesty to deploy troops in Longyou and seek an opportunity to destroy Tuyuhun.
Only by eliminating this foe could Longyou and Hexi be secured, allowing Tang to focus fully on the Western Regions.
Hou Junji's thinking was very clear.
If Tang were to campaign against Tuyuhun, who should serve as vanguard? Naturally, Hou Junji—the man with the most comprehensive intelligence.
Once Tuyuhun fell, Gaochang would be next. That was a victory Hou Junji would not allow to slip away.
With two states destroyed in succession, the army could then press into the Western Regions. With his experience, who else was more suitable to command the campaign?
Because of this, he revised the wording of his memorial several times.
Yet when he returned to Chang'an to report for duty and found not a single former Qin Prince's Residence official in the Three Departments and Six Ministries, Hou Junji sensed that something was off.
The emperor did not summon him.
After some inquiries, Hou Junji learned that the Thousand Ox Guards had sealed off the rear gardens. Aside from personnel from the Directorate of Works, no one was allowed near.
Then perhaps… he should first ask Fang Xuanling what was going on?
Hou Junji knew that since last year, Fang Xuanling had frequently visited the Imperial Academy—partly to prepare preliminary work for compiling the Book of Jin, and partly to study advanced mathematics with the Academy's Chancellor.
Entering the Imperial Academy, Hou Junji saw several students arguing loudly under the sun, holding up a sheet of glass.
Sunlight passed through the glass, scattering patches of light and colors across the ground.
Hou Junji ignored them and hurried inside.
The previous year, he had volunteered to oversee glassmaking using methods from later ages—only to achieve nothing. In the end, the task had been handed to the Directorate of Works.
With broad guidance and the alkali-making method, results came quickly. The glass still contained many impurities, but it had begun to resemble true transparency.
As for what glass was good for? The Directorate of Works simply sent a large batch to the Imperial Academy and let the students puzzle over it.
Crossing the central courtyard and asking around, Hou Junji knocked on another door. Inside, several students and scholars were arguing fiercely.
"When compiling history, how can we mix tales of spirits and marvels with the official record?"
"These accounts are not fabricated! They should be recorded—as reference for future historians!"
Hou Junji looked around. Fang Xuanling was nowhere to be seen.
Disappointed, he left, turned right at the end of the corridor, and knocked on the Chancellor's door.
Granted entry, he was greeted by a sea of paper. Numbers identical to those on the Light Screen filled the pages, making his head spin.
"Minister Fang came this morning," the Chancellor recalled, then shook his head. "He left after noon."
Finding nothing, Hou Junji stood at the Academy gates and considered.
In that case… should he look for Li Jing and Li Shiji?
After learning about gunpowder from the Light Screen, those two generals had gathered many Daoists to study its methods. Their frequent visits to Daoist temples had even earned them censure from the Censorate—something that had nearly made Hou Junji laugh himself sick.
Now, though…
Relying on memory, Hou Junji found the temple—then hesitated.
"Wasn't this temple called Cangsong Temple?"
His attendant explained, "After the New Year, the Duke of Dai personally renamed it."
Hou Junji looked up again at the neat plaque reading Five Thunder Temple, shook his head, and walked in.
He was immediately stopped by the guards.
"General, please hand over any fire strikers."
The guard pointed to a signboard nearby, emblazoned with stark words:
Anyone who brings fire into Five Thunder Temple—beheaded.
Signed below, even more strikingly: Li Shimin.
Hou Junji had no temper left at all and obediently complied.
The Five Thunder Temple was utterly transformed from the year before. It was closed to outsiders. The halls that once housed statues now served as small storage rooms, each with a sign out front:
"Charcoal.
Cinnabar.
Realgar.
Sulfur.
Saltpeter.
Cane sugar.
Orpiment…"
Hou Junji read them aloud and understood at once—these were alchemical ingredients, now all repurposed for making gunpowder.
The temple now operated under strict procedures. Daoists first wrote a formula, then imperial guards fetched the materials. Everything was set up in a separate room, where designated guards ignited the mixture to test the result.
Afterward, a written report was compiled and archived.
Hou Junji felt he had no place to intervene at all. Worse still, neither Li Shiji nor Li Jing was present.
"They're said to be accompanying His Majesty north of the city," a young Daoist told him.
At that very moment, a loud explosion echoed from behind the main hall, followed by billowing smoke.
The Daoist's face lit up with joy.
"Ah! Excellent!"
"Senior Brother Songcheng has attained the Way!"