The Hidden Oracle was written by Rick Riordan.
Apollo is the most important god and the most beautiful as well. Or at least, that´s what he claims to be. But that was all before he crash-landed in a dumpster, as a mortal teenager called Lester Papadopoulos. To become a god again he has to protect the hidden oracle from an enemy called ´the Beast´. If he fails, he will be stuck as a teenager forever.
If you´ve been reading Rick Riordans´ books since Percy Jackson you´re probably as excited as I am for the fact, that this is is a series with Apollo as main character. Apollo is literally the best god ever (fight me if you think otherwise). If you haven´t been in the Rick Riordan fandom (more like: please stop writing books, I´m poor) since the beginning then I highly recommend you to read the Percy Jackson and the Heroes Of Olympus series first. That´ll make it a tiny bit easier to understand The Hidden Oracle.