When TV naturalist Emmet Cole disappears in Brazil, he is declared dead after six months. However, his wife Tess detects a GPS beacon signal from him and a network camera crew agrees to accompany her on the search for her husband. However, they will only finance the trip if Emmet's son Lincoln goes with her. The crew go down the Amazon River and follow the GPS beacon, but find far more than they are counting on when they unearth a spectral creature.
Jahel is possessed by Emmet's spirit and he begs his family to stay away for their own sakes. However, Tess persists and the group find a spirit tree decorated with dolls. A child's ghost stalks them and it soon becomes clear that it wants something from them... and will stop at nothing to get it.
When the crew intrudes upon the Morcegos tribal grounds, all of them are stricken blind except for AJ, who must wrestle with his conscience while the tribesmen close in on his helpless teammates.
The Magus crew find a survivor from Emmet's expedition... suspended by his neck from a noose in the middle of the jungle. The man, Jonas Beckett, is still alive but claims he has no idea where he been for the last six months. As the ship is plagued by insects, storms, and animated vines, the crew realizes that Jonas is cursed, and everyone is willing to sacrifice him except Lincoln.
A mystery ship runs the Magus aground, immobilizing it. The next day, another ship, the Exodus, responds to their Mayday and the crew offers its support... but they're not what they seem.
The Magus crew arrive at Sahte Falls and find footage that Emmet filmed of the days leading up to his disappearance. Lincoln and Tess have no choice but to watch as Emmet battles for survival on his way to the mysterious Source of all magic. Meanwhile, Lena has a confession to make to one of her crewmates.
The Magus explore the abandoned research facility and discover it isn't as empty as they believe. Meanwhile, Tess and Lincoln make a startling discovery, and Kurt has to decide what he will sacrifice to keep his crewmates safe.
With Emmet alive and well and back on board the Magus, the crew sets sail out of the Boiúna and back to the Amazon. However, when a hidden killer shoots one of the crew, Johel draws upon a dark ritual to bring them back to life... with tragic results.