Deep in the Brazilian Amazon lurk tales of a massive one-eyed monster. With slashing claws, savage howl, noxious stench and a gaping mouth in its body, the locals tremble to repeat its name: mapinguari. To gather concrete information on the creature, Spain must gain the confidence of the local tribes. He takes part in an extreme initiation ritual: wearing gloves lined with venomous bullet ants. The insects' stings send Pat into a hallucinatory world of pain.