Deep in the Peruvian Amazon, the Mashco Piro are believed to be the world's largest isolated Indigenous people, having fled into the forest more than a century ago during the rubber boom's violence. The film follows anthropologists, river villagers, missionaries, and loggers who all have a stake in what happens next, as sightings along the riverbanks grow more frequent and the question of contact becomes urgent rather than theoretical. Interviews trace the history of the rubber-era atrocities that pushed the tribe into isolation and the fragile logic that has kept them there since, while footage from the river shows how close encounters have already come. Rather than settling the debate, the documentary lays out the competing interests pulling at an uncontacted people: researchers wanting knowledge, missionaries wanting souls, criminals wanting land and labor, and the Mashco Piro themselves, whose intentions can only be guessed at from a distance. It closes without resolving whether first contact should happen at all, treating that as the genuine open question it is.