This Post is Spoiler Free! The Hidden Oracle I’m going to keep this short because it is a five book series and I don’t want this post to go on foreeeeeeever. So here we go. The Hidden Oracle, book one of The Trials of Apollo (ToA) by Rick Riordan. It is the third and final series in the Percyverse—Percy Jackson and the Olympians (PJO – five books) and The Heroes of Olympus (HoO – also five books) came before it. This review will most likely contain spoilers for PJO and HoO, though nothing too big. Just character names and possibly relationships (that would be impossible to avoid if you ever…