When Percy Jackson discovered that he was a demigod, the son of Poseidon and a mortal, his life changed forever. Along with his companions, Annabeth and Grover, he undertook daring quests: he found out who had stolen Zeus's lightning bolt, brought the Golden Fleece to Camp Half-Blood, and rescued the captive goddess Artemis, determining the outcome of the great Battle of the Labyrinth.

But now the time has come for judgment... I'm telling you this to avoid any misunderstandings: I didn't want to be a demigod. If you're reading this book just because you think you might be one too, then here's my advice: close the book immediately! Don't say I didn't warn you later. My name is Percy Jackson...

The time for the final confrontation has come. All year the demigods have been preparing to clash, alongside the Olympians, with the fearsome forces of Cronos and the Titans, in a battle that seems unequal. While the Olympians fight to thwart the destructive Typhon, Cronos begins his advance toward Olympus, which is essentially unprotected.

During this epic battle, many secrets will be unveiled, such as the terrible prophecy connected to Percy’s sixteenth birthday. And a key role will be played by the elusive Last Olympian, or perhaps the last goddess of Olympus...