I have faith in Riordan again.
Right when I thought the Percy Jackson series was for children, I forced myself to read the second book in Riordan's second Greek mythology arc, called the Heroes of Olympus.
Percy has no memories of the entire first arc, where he blew up Kronos, and all that stuff. He finds a Roman camp, and later finds that a switheroo from Hera/Juno took place, switching the best hero from each camp (Half-Blood and Jupiter) in an attempt to make peace between the two, so both sides can defeat the Mother Earth, Gaea. Last book was Jason, the praetor of Jupiter, and his story at Camp Half-Blood (still debating if that name is good or not...) and Percy's is about going to the north to free the guardian of death, Thanatos. Without Thanatos, beings who died long ago are returning, monsters no longer go to Tartarus, and eventually Gaea will be able to free all of the giants and destroy the gods. View at phoenixpubliclibrary.org