In the stone village at the foot of the Taihang Mountains, Shuan Zi, known as the "idiot," is driven out of his home by his sister-in-law and takes shelter in the dilapidated Temple of the Mountain God. Though seemingly foolish, he silently guards the village: blocking a knife for the widow Hong Yu, saving a child who fell off a cliff, and carrying her on his back to the hospital through a snowy night. The mining disaster three years ago that took Hong Yu's husband hides a shocking secret involving clan head Wang Fu Gui and village bully Da Hu—shoddy safety ropes, embezzled compensation funds, and premeditated murder. Shuan Zi, who has feigned idiocy for three years, uses his silence to gather evidence of their crimes, and with the help of Hong Yu and his childhood friend Jian Guo, finally brings the truth to light before the world.