In the 37th year of Kangxi's reign, Eighth Prince Yinsi traveled south to Suzhou. When heavy rain caused the dikes to burst, he witnessed Yixiu, an illegitimate daughter of the Ulanara clan, save disaster victims with a clever plan. She used waterwheels to divert the floodwaters, and her insight that “water conservancy is the people's livelihood” deeply moved Yinsi. With her talent for governance, Yixiu overcame Consort De's schemes and helped Yinsi crack a salt-tax case in Jiangnan. In the end, Kangxi made an exception and granted her marriage to Yinsi as his principal consort.
After entering the Eighth Prince's residence, Yixiu used firm measures to overhaul its affairs, introducing a “Record of Merits and Faults” to ensure fair rewards and punishments. She also used her business acumen to help Yintang and Yin'e avoid disaster and put their efforts toward legitimate pursuits, earning the respect of the Ninth and Tenth Princes. Meanwhile, her elder sister Rouze became Yinzhen's secondary consort. After losing a child and falling out of favor, Rouze grew increasingly ruthless and joined forces with the Nian clan to frame Yinsi's faction, only for Yixiu to see through her plot.
At court, Yinsi won popular support with a new policy taxing land by household rather than by individual, while Yixiu secured the rear by controlling the vital grain and salt supplies. When Yinzhen's attempt to seize the throne with Galdan failed, Kangxi passed the throne to Yinsi on his deathbed. The new emperor ascended the throne, and Yixiu was made empress. Together, they lifted the ban on maritime trade and established schools for girls, creating a prosperous and enlightened age through their joint rule.
