Paleontologist Helena Walker awakens on a mysterious island populated by extinct creatures. Thrown into a strange world filled with prehistoric beasts and people from throughout human history, Helena must adapt to her dangerous new surroundings.

Helena is wounded and desperately on the run from Nerva's scouts, when she meets a new ally: Meiyin, a righteous rebel from ancient China. Together, they attempt to investigate the mysterious Green Artifact deep within a hazardous cave.

Helena and Meiyin find new allies in a treetop village led by Lakota warrior John and his adopted daughter Alasie. A sickness ravaging the villagers brings everyone together in a quest to reach the mountaintop Pteranodon den that may hold a cure.

Helena and her allies attempt to liberate the prisoners at a brutal mining camp. When Helena's plans go awry, she and Alasie face-off against a sadistic camp warden called 'The Gladiatrix', and must stage a dino-powered breakout.

Meiyin attempts to turn the newly-liberated villagers into soldiers, but her comrade Henry argues against her military leadership. Nerva stages a counter-attack against John's village, to devastating effect.

Imprisoned in Nerva's fortress, Meiyin recalls the tragic mistakes of her past. Helena, John and Henry attempt to stage a daring rescue of Meiyin, but it comes with tremendous sacrifice.