The morning Lin Wan'er was named Minister of Finance dawned with the sound of bronze bells and the scent of ink drying on imperial decrees.
She stood in the Hall of Supreme Harmony, her hu fu glowing faintly against her new crimson robes. Prince Li Longji—now Emperor Xuanzong—placed a golden seal in her hands, its surface etched with the Mi Zhen Si's star symbol.
"With this," he said, his voice echoing through the chamber, "you command the Hubu Bank—the first central bank of Tang."
Wan'er bowed deeply. "I will not fail you, Your Majesty."
But as she left the palace, a shadow detached itself from the pillars—Captain Pei Ji, his scarred face taut with tension. "We need to talk," he said, pulling her into a side corridor.
He handed her a scroll. "The Mi Zhen Si intercepted this from Luoyang. Princess Taiping is alive—and she's forged an alliance with the Uyghur khanate."
Wan'er's blood chilled. "What does she want?"
"Control of the Hubu Bank." Pei Ji hesitated. "She's offering to marry the khan in exchange for an invasion force."
Wan'er activated her calculator, inputting data on Uyghur military strength and Tang's financial reserves. "We need to raise funds—fast."
She spent the next three days drafting the Kaiyuan Financial Reforms: a new currency system, a centralized treasury, and strict lending regulations. As she worked, a veiled woman slipped into her office.
"Your Highness," she whispered, removing her veil. "I am An Lushan's sister, An Lushun. My brother has declared independence in Fanyang—and he's offering you a trade deal."
Wan'er's eyes sharpened. An Lushan was a powerful general with ambitions of his own. "What does he want?"
"Exclusive rights to mint Kaiyuan Tongbao," Lushun said. "In exchange, he'll provide iron for your bank's vaults."
Wan'er activated her calculator. "Iron is critical for coin production… but granting minting rights would cede financial control."
She hesitated, then nodded. "Agree to the terms. But include a clause allowing the Hubu Bank to audit his operations."
As Lushun left, Pei Ji entered, his face grim. "The Mi Zhen Si has confirmed it—Princess Taiping is en route to Uyghur territory."
Wan'er's mind raced. "We need to disrupt her alliance. I'll issue heqin zhai quan—Marriage Bonds."
Pei Ji frowned. "Explain."
"Investors who buy these bonds will receive a share of the Uyghur trade profits… but only if the marriage is annulled." Wan'er smiled grimly. "It's a bet against Taiping's political future."
The bonds went live the next morning, causing a frenzy in the markets. Investors bet heavily against the marriage, driving up the cost of insuring Taiping's assets.
That evening, Wan'er visited the Hubu Bank's vaults, where workers were pouring molten gold into Kaiyuan Tongbao molds. "How many coins can we produce per day?" she asked the master 铸币.
"100,000 guan," he replied. "But we're running low on copper."
Wan'er activated her calculator. "Allocate 20% of the gold reserves to purchase copper from the Nanzhao kingdom."
The master 铸币 paled. "That's risky, Your Highness. Gold is the cornerstone of our currency."
Wan'er nodded. "But copper is the future. Trust me."
As she left the vault, a commotion erupted outside. A group of huangniu brokers stormed the bank, waving forged Kaiyuan Tongbao.
"Fraud!" they shouted. "The new coins are debased!"
Wan'er's heart raced. This is Taiping's doing. She activated her calculator, inputting data on the forged coins' metallurgy. "These contain 30% lead," she declared. "The real coins are 90% copper."
The crowd hesitated. "How can we tell the difference?" a merchant demanded.
Wan'er handed him a magnet. "Real Kaiyuan Tongbao are non-magnetic. Forgeries aren't."
The merchant tested the coins. "It works! The real coins don't stick!"
The crowd erupted in cheers. The huangniu brokers fled, but not before Wan'er caught a glimpse of their leader—a man with a scorpion tattoo on his neck.
The Tian Xian's mark.
That night, as Wan'er reviewed the day's transactions, a scroll rolled into her office. She opened it, her heart racing.
It was a map of the Mi Zhen Si's hidden copper mines, with a note from the old woman: "Use this to secure the future."
Wan'er activated her calculator, inputting the mine's coordinates. "Pei Ji, we need to send a delegation to Nanzhao."
He nodded. "I'll assemble a team."
As they prepared to depart, Emperor Xuanzong entered, his face taut with tension. "I've received reports of unrest in Fanyang," he said. "An Lushan is amassing troops."
Wan'er's mind raced. If Lushan rebels, our copper supply is at risk.
She activated her calculator, inputting data on Fanyang's economy. "I'll issue pingfan zhai quan—Rebellion Bonds. Investors who buy them will receive tax breaks if Lushan is defeated."
Xuanzong nodded. "Do it. And hurry."
The journey to Nanzhao was perilous. They faced bandits, monsoons, and Tian Xian assassins, but Wan'er's financial strategies kept them alive—using kuajing fuhui to secure supplies, issuing bing zheng zhai quan to hire mercenaries.
Finally, they reached the copper mines, guarded by Nanzhao warriors. The mine's chief, a woman named Mu Guiying, greeted them with a wary smile.
"Princess Mingyue," she said. "We've heard of your Kaiyuan Tongbao. Impressive."
Wan'er bowed. "I've come to negotiate a trade deal. Copper for Hubu Bank bonds."
Guiying's eyes sharpened. "And what guarantee do I have you'll honor them?"
Wan'er activated her calculator, inputting data on Nanzhao's economy. "I'll peg the bonds to your rice production. For every dan of rice you harvest, you'll receive a guan in bonds."
Guiying nodded. "Agreed. But I want a seat on your bank's council."
Wan'er hesitated. Including Nanzhao in the Hubu Bank would strengthen the alliance… but it would also dilute Tang's control.
She nodded. "Done."
That evening, as they sealed the deal, a rider burst into the camp. "Princess Taiping has arrived in Uyghur territory!" he shouted. "She's marrying the khan tomorrow!"
Wan'er activated her calculator, inputting data on the marriage bonds. "If the marriage happens, the bonds default. We'll lose everything."
Pei Ji drew his sword. "We need to stop her."
Wan'er nodded. "I'll go to the wedding. You lead the team to secure the copper."
The Uyghur wedding was a lavish affair, with silk tents and camel races. Wan'er arrived disguised as a 西域 dancer, her hu fu hidden beneath her veil.
As the khan placed a golden crown on Taiping's head, Wan'er stepped forward. "I challenge this marriage!" she declared, revealing her hu fu.
The crowd gasped. The khan frowned. "Who are you?"
"Princess Mingyue of Tang—and the rightful owner of this crown." Wan'er activated her calculator, projecting a hologram of the Mi Zhen Si's marriage contract. "By Tang law, this crown belongs to the Hubu Bank as collateral for Princess Taiping's debts."
Taiping paled. "You can't do this!"
Wan'er smiled grimly. "Watch me."
The khan studied the hologram, then nodded. "The law is clear. The crown must be returned."
As Taiping raged, Wan'er took the crown. "Your marriage is annulled. And your Tian Xian assets are now property of the Hubu Bank."
That night, as they returned to Tang, Pei Ji met them with news. "The copper mines are secure. An Lushan has backed down."
Wan'er nodded, exhausted but triumphant. "We've won."
But as she stared at the hu fu's star chart, now fully illuminated, a new resolve filled her. The financial revolution had only just begun.