The seals are weakening. And if the last Guardian is not there to secure them, an Evil shall be set loose upon the world not seen since its beginning. Ever since the time of the Spanish conquest over the Maya, the family of Juan Guerro has guarded the lost city of Mosh Chaltun, concealing its mysteries as they kept watch. But now an American archeologist has opened Mosh Chaltun, and secrets long buried are beginning to stir. Lacking the knowledge of his ancestors, Juan and the few people allied with him must find a way for him to stand alone against the darkness that is coming. For if Juan falls, there is no one else. And if the last Guardian falls, it will-literally-mean hell on earth.