Deep in the Amazon rainforest, greedy site foreman Buck kills the hatchlings of the ancient serpent spirit Leviathan for black market profit, while only heavy machinery operator Riley Cole tries to stop him out of reverence for the forest. Three years later, Buck brings Riley, her cowardly husband Tyler and a group of company executives back to the rainforest for a team-building retreat. Leviathan returns with jungle monsters to exact revenge, laying siege to the betrayers — yet it spares Riley, who once showed mercy, launching a long-overdue reckoning in the wild.