At the end of the Qing Dynasty, the biological expedition led by Qin Xiaofeng's father is attacked by a mysterious dragon, and the whole team is missing. His father's best friend, Xu Yuansheng, offers a huge bounty to gather a mixed team of dragon hunters to enter the mountain, and Qin Xiaofeng goes with them to find the dragon and save his father.

The film takes the "slow train" driving deep in the mountains and the conductor's boring work position as the carrier, through the main character Cheng Lu, Zhao Dapeng and to Pingping two young college students and young conductors