He Xianlin, a modern environmental protection engineer, encountered strange lightning in the Gobi Desert in Danxia City and traveled to the Jingyang battlefield in the ninth year of Tang Wude (626). Relying on modern military knowledge, engineering technology and environmental protection concepts, he repeatedly made extraordinary achievements on the battlefield in the early Tang Dynasty. He was appreciated by Li Shimin and became his core staff.
During the twenty years of the Tang Dynasty, He Xianlin participated in major historical events such as the Weishui Alliance, the Northern Expedition to the Turks, and the Eastern Expedition to Goguryeo, and promoted military reforms (such as the "wolf pack tactics" and the "three-three system"), technological innovations (improved metallurgy, crossbows, and environmentally friendly military regulations) and the dissemination of environmental protection concepts (proposing "win without destruction" and "sustainable expansion"). He always cared about his modern-day Kazakh wife Ayiguli, and finally successfully returned to modern times on the top of Mount Hua after observing astrological anomalies similar to those during the time-travel.
After returning, He Xianlin discovered that modern times were only twenty years old. He applied the experience of the Tang Dynasty to modern environmental protection work, created an "ecological military industry" concept that integrated ancient and modern times, and realized the unification of personal values in the two eras.
