It's the beginning of a new year and the Cianíans (Keen-ee-en) are coming together for a yearly ceremony known as the Aging. During this ceremony, those that have reached the age of sixteen are sent on a three-month journey over the sea to the Trial Islands to become Aged.Croí (Kree), the last of his family to participate in the Aging, is taken to the Trial Islands along with nine other Agers. Their journey is fraught with peril as they train to develop necessary skills and a sense of teamwork. They will have to overcome various dangers the Island provides, and the likelihood that one of their companions will die.Croí must keep himself and his fellow Agers alive, while navigating the dangers of the Island, as well as his own naivety and personal trauma. Whether he and his fellow Agers survive or not will rely on their ability to adapt and overcome.