Seven biology students venture deep into the Amazon rainforest to collect samples and take notes for a final assignment before graduating. Their chosen location is Supayacu (Devil's Lake), where mysterious disappearances have been reported. Along the way, a series of events transforms their pleasure trip into a nightmare, during which they vanish one by one, unaware that they may have unwittingly encountered—much less accepted—amidst the lush vegetation, a mythological and fateful creature with uneven feet.