When Percy Jackson discovered that he was actually a demigod, the son of Poseidon, his life changed forever.

With his companions, Annabeth and Grover, he undertook two daring missions: he found out who had stolen Zeus's lightning bolt and then brought the Golden Fleece to Camp Half-Blood, necessary to revive Thalia's tree and save the camp.

But the adventure in the world of gods and heroes never ends...

(...) [Excerpt from the text on the back cover of the edition]