One hundred years ago, the Jade Beard Immortal Master sealed the strange beasts of the eight states, and the sacred tree in the southwest turned into a dead tree (turned into a spiritual source). In the 40th year of the Great Zhao Dynasty, the evil cult Gu Niantong wanted to break the seal of the immortal master, refine the sacred tree and turn it into a tree demon to poison all living things. For this reason, the late emperor specially ordered Tang Lingfeng, the hidden supervisor of the Demon Suppression Division, and others to lead the army to the southwest to quell the evil spirits. In order to subdue the tree demon, one needs the mechanical giant beast created by Gongshu Jia, and the method to drive the giant beast is the "Spirit Source Secret Technique" recorded in "Lu Ban Complete Book". This has therefore implicated the blood feud between the Tang family, Gongshu Jia, and the Demon Suppression Division more than ten years ago. Decades ago, Gongshu Jia slaughtered the entire Tang family in order to obtain the "Lu Ban Complete Book". Tang Lingfeng, who was only eight years old and escaped by chance, was taken back to the Demon Suppression Division by Zhang Qian, the commander of the Demon Suppression Division, to be raised. Here, Tang Lingfeng met Lu Yin and Lu Tong, brother and sister. The three of them were as close as brothers and sisters, and together passed the strict assessment and became members of the Hidden Supervisor. As Tang Lingfeng's life experience was revealed, the relationship between Tang Lingfeng and Lu Yin and Lu Tong changed, and the three of them quietly fell into the conspiracy of Gongshu Jia.