Percy Jackson is trying to overcome his almost overdue tuition fees. He is expelled from school again, and he never imagined that his algebra teacher would turn into a terrifying monster that kills him! Is this what he imagines, or is this only the beginning of what is more dangerous? When his mother finds out, she decides that it is time for him to tell Percy the truth, which will be upside down. On the one hand, his family is not a basic family at all.