The Tyrant's Tomb

Turned into a human and banished from Olympus, Apollo must restore five ancient oracles to reclaim his godly powers. Apollo (aka Lester Papadopoulos) is now at Camp Jupiter in the San Francisco Bay Area, where the Roman demigods are preparing for a desperate last stand against the evil Triumvirate of Roman emperors. Hazel, Reyna, Frank, Tyson, Ella are among those who will need Apollo's aid to survive the onslaught. It may be time for him to call home-- but will anyone on Mount Olympus pick up? -- adapted from Goodreads info and jacket