Borne and Trieste are young lovers from radically different backgrounds, on a world shaped by mysterious entities known as the Guardians. These guides established a stable and prosperous path for humanity to follow, but are now gone, and the world faces its greatest crisis in history -- a catastrophic volcanic eruption has led to famine, disease, and war. Borne is wounded on the field of battle and struggles to survive. Trieste, torn in multiple directions, must choose between following her heart and following her sense of duty. And the leading adherents of the Guardians struggle to keep global society from collapsing entirely.