Wu Xie, Pang Zi and Liu Sang, who was tasked with taken the unconscious two to the city, are involved in a car accident by the revenge driven Jiang Zi Suan and are rescued by soldiers from a mining work camp. They soon start running out of time, when Zi Suan finds them and plans to buy them from the soldiers. While in the underground river, the exploration group find a secret map to the mysterious Thunder City but are taken hostage by Boss Jiao.