Liu Heng, a modern electronic physics researcher, accidentally traveled to the prosperous Tang Dynasty due to an electromagnetic accident in the laboratory. He brought modern physics knowledge such as mechanics, electromagnetism, and fluid mechanics to his mark in Chang'an: he used pulleys to improve water wells to lift water, used thermal expansion and contraction to build the roof of the Daming Palace, and used acupuncture and water distribution to circulate hot compresses to treat illnesses. In the court, he designed a copper wire telegraph to help Emperor Suzong Li Heng of the Tang Dynasty, who was still the prince at the time, and used fluid mechanics to cut Yang Guozhong's salt fortune.
On the eve of the Anshi Rebellion, he forewarned that An Lushan's rebellion was rebuked, so he secretly contacted Guo Ziyi to rectify the ordnance. After the rebellion broke out, he brought modern first aid skills to rescue the wounded, used sonar principles to help Qixiufang break out of the siege, and assisted Li Heng in Lingwu to build city defenses.
Entering the Tang Dynasty with his knowledge of physics, he struggled amidst intrigues, rivers and lakes, and wars. He not only had to use science to reverse the decline of the Tang Dynasty, but also had to deal with the suspicion of imperial power and the turmoil of the times.
