A picture of a prosperous era

As the bugle call of the Double Ninth Festival resounded throughout Chang'an, Emperor Gaozong (Li Zhi) was holding Princess Taiping while inspecting the canal transport convoy at Chengtian Gate.

Eight hundred new-style grain carts were fully loaded with rice from the Jiangnan region, and each cart was uniformly decorated with a sun and moon flag.

Crown Prince Hong, dressed in court attire, stood by his side, carefully adjusting his sister's jeweled crown, which had been disheveled by the wind.

"Your Majesty, please look," Wu Meiniang pointed to the last ten grain carts covered with blue curtains, "these are lychee trees newly sent as tribute from Lingnan. They will bear fruit at Mount Li next year. The greenhouse cultivation method proposed by the Crown Prince the other day is perfect for cultivating these fine trees from the south."

Taiping reached for the sachet at her father's waist, and Li Zhi lifted his daughter up.

This action brought tears to Cheng Wuting's eyes—three years ago, the emperor didn't even have the strength to lift his daughter.

Prince Hong stepped forward at the opportune moment and steadily supported his sister's back.

(OS: Hong'er is becoming more and more like a crown prince, knowing how to be considerate in the details.)

At noon, Emperor Gaozong (Li Zhi) personally placed the original copy of the "Sun and Moon Code" into the Imperial Ancestral Temple.

As he carried the ten-pound jade box up the hundred steps, Wu Meiniang noticed that there was no cold sweat on his forehead.

Crown Prince Hong followed closely behind, holding the secondary register with the air of a future seal-holder.

"The ceremony is complete—" As the master of ceremonies chanted, Li Zhi suddenly turned to the officials: "I wish to confer upon Taiping the title of Princess Zhenguo, and appoint the Crown Prince to oversee the state and assist in the new policies for grain transport."

Amidst the uproar in the court, the eight-year-old princess, holding the golden seal, said in her childish voice, "Your subject wants to help Father and Mother manage the canal transport school well."

Crown Prince Hong added with a smile, "Yesterday, my sister and I discussed the 'Records of Rivers and Canals,' and I found her proposed method of linking sluice gates to create a rather ingenious system."

(OS: Well done, Hong'er! He saved face for his sister while also displaying the demeanor of a crown prince.)

That night, Wu Zetian discovered Princess Taiping's "toy" in her bedchamber—a children's version of the "Map of the Four Seas," on which three new canal routes were marked with rouge.

Even more astonishingly, one of them perfectly matches the canal rerouting plan secretly discussed by the Ministry of Works.

Meanwhile, Prince Hong's reading notes contained suggestions for improving the plan.

"Your Highness," Shangguan Wan'er's hands trembled as she held the report, "His Highness the Crown Prince inquired today whether my sister's new plan for the grain transport route could be included in next year's project."

As Wu Meiniang gazed at the profiles of her children sleeping peacefully side by side, she suddenly remembered the "Memorial of Princess Zhenguo to the Japanese Silver Mines" that she had seen in the museum before her time travel, next to which was the "New Interpretation of the Grand Canal" written by Crown Prince Hong.

(OS: It turns out that the story of the brother and sister's harmonious relationship recorded in historical books was already foreshadowed at this moment.)

When the moonlight filled the courtyard, Li Zhi found his wife and daughter by the hot spring pool.

Taiping was drawing a picture of a ship on the sand with a bamboo stick, while Prince Hong squatted beside him, carefully adjusting the proportions of the sails and ropes.

Upon seeing his parents arrive, the young crown prince respectfully reported, "Your subject believes that my sister's design for a blessed ship can be tested in Dengzhou first."

"Meiniang," Li Zhi gently stroked his wife's shoulder, "our children are all contributing to the prosperity of this land."

Wu Zetian carefully put away her children's design drawings, then suddenly laughed and said, "Your Majesty should increase Di Renjie's salary—the 'brother-sister co-rule' clause in his newly revised 'Sun and Moon Laws' seems to have been written specifically for our family."

(OS: Since history has already gone astray, let's make this deviation a little warmer.)

When the historian wrote in the daily records, "In the third year of the reign of Emperor Wu Zetian, Princess Zhenguo presented a new plan for the grain transport, and the Crown Prince assisted in the administration," no one knew that Wu Zetian had secretly drawn half a sun and moon on the palms of both her brother and sister.