In a time far removed from modern civilization, primitive tribes battle for survival in a harsh and unforgiving prehistoric world. Tumak, a member of the Rock Tribe, is cast out following a violent disagreement with his father, the tribe leader. Wandering alone and vulnerable, Tumak encounters the Shell Tribe, a more advanced group with a peaceful demeanor and refined way of living. Here, Tumak meets the compassionate Loana, who helps him understand cooperation and civilized behavior. Gradually, Tumak starts integrating into the Shell Tribe's way of life, learning their customs and developing a bond with Loana.

Back in his homeland, Tumak's absence triggers unrest within the Rock Tribe, struggling under oppressive leadership. Meanwhile, Tumak faces internal and external challenges that test his capability to adapt to new norms while surviving the dangers of a prehistoric landscape teeming with predatory creatures and natural disasters. After dangerous encounters with fearsome beasts, and grappling with primal instincts, Tumak finds himself at a crossroads where he must confront his past and make crucial decisions that will impact his future as well as the fates of both tribes.