Apollo, the once glorious god of the sun, music, poetry, and more, has been cast down to Earth in punishment by Zeus. Now he is an awkward mortal teenager named Lester Papadopoulos. In order to regain his place on Mount Olympus, Lester must restore five Oracles that have gone dark. But how is he supposed to accomplish this task without having any godly powers? It's time to recruit some help. A certain demigod named Percy Jackson shows him where he needs to go: a training camp on Long Island called Camp Half-Blood.
By making him human.

After angering his father Zeus, the god Apollo is cast down from Olympus. Weak and disoriented, he lands in New York City as a regular teenage boy. Now, without his godly powers, the four-thousand-year-old deity must learn to survive in the modern world until he can somehow find a way to regain Zeus's favor.

But Apollo has many enemies-gods, monsters, and mortals who would love to see the former Olympian permanently destroyed. Apollo needs help, and he can think of only one place to go . . . an enclave of modern demigods known as Camp Half-Blood.