Tris is a sylvan, which is a type of tree-folk who are the children of the god of the forest. Tris is a guardian of the forces of nature, especially plants, so he can use plants for magic. This includes wood, so he can use wood as a sensory organ, or make it turn into powder, and then re-form. Tris loves to use his magic powers for healing people, but magic is forbidden among humans, so he pretends that he is just using medicine. Tris originally lives in an enclave with other sylvans, but he never really fits in, because they are only motivated by fear of discovery by humans. The sylvans once had huge forests to rule over, but humans have destroyed many of the forests, driving them back.