The Academy of Night and Day has been around for centuries, if not more. In a world where most don't even know the Academy exists. While most of those that do, don't even know what takes place within its walls. It only takes those most likely to pass the tests, or those who have recommendations from its teachers or those who have already graduated. What goes on within, however, is far more worrying than rigorous tests and the demands of a social life in an exclusive boarding school.
Nico Di Angelo is a new student at the Academy, along with his sister, Hazel Levesque. Upon arrival, they, along with the other new students, are told not to leave their dorms at night, with the same message repeated over dinner. What is strange about it is they are told leaving could cause serious injury, or even death. Then he finds out he is a Nocte, or Night, student, While Hazel, the only piece of familiarity in this strange school, is a Dia, or Day student. It also doesn't help that his dad is the Assistant Headmaster.
Percy Jackson is starting his third year at the Academy. Being a Nocte student has its upsides. Such as being a vampire, not sharing a room with a human Dia. But, unlike his two previous years, he is sharing a room with someone. Someone who is a freshman. Who has a Dia sister and may have PTSD. From what, no one knows but him, Hades, and his sister. There is also the little fact that he seems to be completely, utterly, and deliciously, Human.