The Nanuak is the world soul, something that the Raven Clan Mage, Saeunn, once described as a 'river with no end'. Each living thing has a part of the Nanuak in him and one of his three souls; the only one that can never be detached from him, even in the event of death; is the Nanuak. It is presumably what allows the various sentients of the Forest to communicate with one another and even discover the ways of others. These parts of the Nanuak were so strong that they could absorb the part of the world soul in other living beings if they touched them with their bare skin.