In post-apocalyptic Colombia, a group of survivors are organised as a tribe, a primitive society without technology. They form a small village in the Grey Rock National Park surrounded by beasts that transmit a disease that transforms the victims into mutants. The tribal leader is Uri, whose son Savan is the best hunter of the tribe and his father's successor. Kaleb is the best tracker. Kaleb and his sister Miru (Eleanor Tomlinson) are the only literate survivors. Their father Jaret believes other survivors might exist outside the park and encourages them to investigate this. Kaleb, a dreamer, is secretly in love with Savan's woman, Dorel. When the beasts attack Uri's hamlet, a group runs to a cave and blocks the entrance with logs. Kaleb saves Dorel from a beast, at which point they become romantically involved while Savan looks on.