In the future, the greenhouse effect intensifies, the environment deteriorates, and people are forced to build and move underground. Scientists painstakingly develop temperature balancers and build underground trains, hoping to lead everyone back to the surface to rebuild their homes. However, on the day of the emission plan, mutant giant lizards landed and wreaked havoc, poisonous gas spread, and disaster struck... Led by train engineer Wang Ge, the survivors embarked on a desperate escape journey.