The Heroes of Olympus, Book One: The Lost Hero

Jason wakes up on a school bus holding hands with a girl he's told is his girlfriend, with no memory of anything before that moment — not her name, not his own history, not why he's a student at Wilderness School, a boarding school explicitly for "bad kids." Rick Riordan opens the book this way and then splits the narration three ways, between Jason's disorientation, his friend Leo's knack for building things, and Piper's own secret she isn't telling anyone, so the mystery of what happened to Jason gets filled in from multiple angles rather than one. At 589 pages, it's a substantial follow-up to the Percy Jackson books, continuing that universe with a new set of demigods.

The mythology here draws on both Greek and Roman versions of the gods, which gives Riordan more material to work with than the first series had, and the book uses that expanded mythology to raise the stakes of the quest Jason and his friends get pulled into. Rotating narrators mean a reader who connects more with Leo's humor than Jason's memory-loss plot, or vice versa, still has a way into the book, which matters for a cast this size. Best suited to a reader who's already finished the Percy Jackson series and wants the world to keep expanding rather than starting over with unfamiliar rules.