The Weight of Royal Trust

Returning to Xianyang, Cai Ze felt an unshakable burden pressing upon him. The old King of Qin had adopted his “Eight-Character Strategy to Stabilize Qin,” which came as no surprise. However, being entrusted with the monumental task of determining the royal succession—a matter Cai Ze never anticipated handling—left him deeply unsettled.

In the Warring States period, establishing an heir apparent was traditionally considered state affairs where ministers could participate in discussions or evaluate candidates’ virtues. Yet the selection of a crown prince’s primary heir lacked clear regulations. Among nobility, unless it involved royal power struggles, determining primary heirs was typically treated as family matters. When succession impacted the royal power structure, the monarch would decide the extent of intervention based on circumstances. The most notable precedent occurred during King Wei of Qi’s reign when Chancellor Jing Guo Jun Tian Ying, lacking a primary heir, had his secondary son Tian Wen designated as primary heir by royal decree, who then became the famous Lord Mengchang.

The current situation in Qin bore far greater significance than the Lord Mengchang affair. The selection of Crown Prince Ying Zhu’s primary heir directly concerned the imperial succession—a matter that should have been handled personally by the King of Qin. Why then was this responsibility thrust upon Cai Ze?

The Perils of Court Politics

The true challenge lay not in the matter’s importance or public scrutiny—Cai Ze feared no difficulty, believing true achievement emerged from overcoming crises. The crux was that selecting the crown prince’s heir directly affected the interests of various royal family branches, presenting numerous thorny issues where every move risked collateral damage. For an outsider minister, this was exceptionally difficult to manage.

Moreover, the Warring States period celebrated military and administrative achievements. Famous statesmen expanded territories through warfare or enriched nations through governance. Palace intrigues rarely brought visible accomplishments and didn’t play to scholars’ strengths. Even Fan Ju, with his renowned diplomatic skills, had only briefly evaluated royal heirs at King Zhao of Qin’s command before resigning as chancellor after three months—a telling indication of the challenges involved.

Cai Ze understood his limitations clearly. In terms of seniority, prestige, achievements, and diplomatic ingenuity, he considered himself mediocre compared to Qin’s legendary chancellors like Shang Yang, Zhang Yi, Wei Ran, and Fan Ju. Even these towering figures had ultimately failed in the treacherous palace politics of declining powerful monarchs. How could Cai Ze, who wished to avoid such entanglements, suddenly find himself solely responsible?

The Compelling Evidence

Yet Cai Ze accepted the mission, compelled by a box of confidential documents the King showed him. These included memorials from senior ministers about selecting the crown prince’s heir, Fan Ju’s investigative reports on various princes, and Crown Prince Ying Zhu’s self-assessment. Most startling was a secret memorial from Shi Cang, a hermit from Hexi, who offered an eight-character evaluation of the crown prince’s sons: “Unlearned in statecraft, only fond of archery and horsemanship.” The blunt conclusion read: “Shi Cang, a commoner, speaks frankly: If these royal grandsons don’t study statecraft, Qin faces peril!”

This memorial forced Cai Ze’s hand. Shi Cang had been secretly recommended by Fan Ju to tutor Ying Xi, the sixth son of Lord Anguo (Crown Prince Ying Zhu), through Cai Ze’s own mediation. By protocol, both were guilty of “private recommendations.” With this secret that bypassed the old King of Qin, accepting the royal commission became Cai Ze’s only way to mitigate the offense. Moreover, having become chancellor based on his expertise in statecraft economics, how could he refuse?

The Mysterious Messenger

Troubled by unanswered questions, Cai Ze decided to first notify the crown prince’s residence. His carriage arrived at the estate where the steward informed him the crown prince was by the pond pavilion. Waving off formalities, Cai Ze waddled directly toward the waterside.

Spotting the stone pavilion, he chuckled: “Such fragrance! Who says good medicine must taste bitter?” Crown Prince Ying Zhu, having just set down his medicine bowl, stood and clasped hands: “The newly appointed chancellor seems carefree indeed! Lord Gangcheng proves his great talent!” Cai Ze mysteriously waved his hand: “Mockery serves no purpose. This old man is like a grasshopper tethered to a turtle’s leg—no hopping about.”

Their conversation was interrupted by a royal decree announcing that Crown Prince Ying Zhu would oversee government affairs according to Cai Ze’s strategies, effectively making him acting chancellor. The bewildered crown prince turned to Cai Ze: “What does this mean?” Cai Ze calmly explained this likely resulted from the crown prince’s recent memorial and represented an opportunity to familiarize himself with state affairs before succession.

The Merchant Strategist

That evening, as rare cool breezes relieved Xianyang’s summer heat, Cai Ze arranged his study materials in the courtyard for comfortable nighttime reading. A steward announced a visitor—a scholar named Lü Buwei from Puyang, bearing a message. Initially dismissive, Cai Ze changed his mind upon hearing details and received the guest.

Under the crescent moon, the white-robed visitor moved with elegant grace, exuding an amiable aura. Lü Buwei presented a slender bronze tube containing a secret letter from Fan Ju, now retired. The letter revealed that Ying Yiren, a long-lost grandson of the crown prince, had been located in Zhao through Lü Buwei’s efforts—information potentially crucial for the succession decision.

The Chess Master’s Gambit

Their subsequent meeting at Lü Buwei’s modest lodgings—named “Xiuzhuang” (Cultivation Manor) after a Xunzi quotation about self-correction—revealed deeper layers. Their conversation ranged from literature to a demonstration of Lü Buwei’s remarkable mathematical abilities calculating possible Go board configurations. Over a game where Cai Ze triumphed, they bonded through shared intellectual pursuits.

When Cai Ze examined his prize—an exquisite Go set with jade pieces and a board inlaid with pearls—he marveled at its refinement. Lü Buwei explained the set’s origins from his trading ventures, emphasizing that true value transcended monetary worth. Their discussion turned to Fan Ju, with Lü Buwei explaining their limited acquaintance and producing the original letter to verify his story.

The Statesman’s Dilemma

As their wine deepened, Cai Ze finally broached the political implications. Fan Ju’s letter, while providing valuable information about the missing heir, raised questions about potential ulterior motives. Could this be part of some larger scheme? The mysterious involvement of Shi Cang, Fan Ju’s recommended tutor who unexpectedly memorialized the king, added another layer of uncertainty.

Cai Ze faced a classic Warring States dilemma: how to navigate royal succession politics where every move could have monumental consequences. The discovery of Ying Yiren provided an alternative to Ying Xi, creating welcome flexibility in the selection process. Yet the channels through which this information arrived—potentially tainted by factional interests—demanded cautious handling.

The historian Sima Qian would later document these intricate power struggles that shaped Qin’s path to unification. Cai Ze’s predicament epitomized the challenges faced by officials during this turbulent era—balancing duty to state, monarch, and personal survival amidst the deadly games of thrones that characterized the Warring States period’s closing chapters.