Ep 7. Season I - Episode 07 - The Invisible Enemy

Ito takes the amulet and, when he tries to use it, he unleashes an invisible creature which threatens the tribe. When Enyo realizes what Ito has done - and that the creature is bent on destroying Hunga, he also deduces that the creature is Ito's anger given form! He has to find a way to neutralize it and save Hunga before it's too late.