Zhang Lin, a doctor of theoretical physics, was accidentally brought into Chang'an of the Tang Dynasty with a bloody jade pendant while cleaning up his grandfather's ancestral home. For the first time, she meets Li Ruoxin, the legitimate daughter of the Duke of Qing, who looks exactly like her late love Wang Yutong. She accidentally ends up living in the Duke's mansion as a handyman.
He used modern knowledge to transform food boxes and repair waterwheels to help the government resolve the water transportation crisis. However, the credit was stolen by Han Yingjie, the prince of Rongguo, and was clearly rejected by Li Ruoxin. Later, he was jealous and imprisoned by the prince because of the theft of the drawings. When the firewood shed caught fire, the jade pendant changed and helped him return to modern times.
After returning, Zhang Lin found that he had the power to control water, but was declared dead and his old house was about to be disposed of. In an accident, he traveled back to the Tang Dynasty again, got involved in the palace crisis, experienced life and death with Li Ruoxin, and awakened the power of chaos. The two went to the Kunlun Ruins to explore the secrets of the jade pendant and their own power, awaken the will of the halo, and faced the choice of staying as a guardian or returning to the mortal world, and finally chose to return to Chang'an with their power.
After returning to the Tang Dynasty, they witnessed the destruction of the Duke's Palace. In addition to their grief, they launched a final showdown with Li Heng in front of the Tai Chi Palace who attempted to seize power through a blood sacrifice. They used the power of the Nimbus to kill Li Heng and seal the betrayer Can Nian. After the crisis was resolved, the two declined the position of national master and chose to assume the mission of Yongzhen's time and space anchor and protect the world.
