Watch Monster 2: Prehistoric Alien (2020) : Full Movie Online Free Li Jian is an expert on cave exploration. Because of a drunk driving accident, his son Xiaoyu suffered a lifelong disability on his left foot. His wife Liu Yun could not forgive Li Jian for filing for divorce, and Li Jian was deeply guilty and self-blame for this. In order to realize Xiaoyu's birthday wish to reunite with his father, Liu Yun took Xiaoyu to the place where Li Jian worked. The sudden vortex in the lake sucked Li Jian's family into the mysterious cave deep in the earth. Deep in the heart of the earth, there are dangers, bloodthirsty humanoid monsters, and dangerous alien behemoths. In order to protect his wife and children from escape, Li Jian began the most difficult and dangerous geocentric adventure in his life.