Noah, Donald et Solorio, having rescued the rest of the children kidnapped by the ruthless gold prospectors of the Palombian rainforest, have escaped up the Boavista River, despite the rumours of terrible danger in that region. One evening, frightened by, yet drawn towards, demented laughter in the distance, they discover a lost temple, and at its top, a mysterious light. Worried about them, the Marsupilami soon joins them again – and not a moment too soon …