A half-blood of the eldest gods,
Shall reach sixteen against all odds,
And see the world in endless sleep,
The hero’s soul, cursed blade shall reap.
A single choice shall end his days,
Olympus to preserve or raze.

The Great Prophecy, long withheld by the Oracle, has now been revealed. But like most prophecies, its meaning is unclear. Is the half-blood Percy, or another demigod born of the Big Three? Who is the hero, and what is the cursed blade? And what about the last line—is Olympus destined to survive or fall?

The answers have never been more important, for Kronos, the lord of time and king of the Titans, has risen from Tartarus. His essence has taken over Luke Castellan’s body and mind. Now he and his army of fellow Titans, monsters, and giants are raging across the country toward New York City. There, they will focus their attack on Manhattan, specifically the Empire State Building and Mount Olympus high above it. They will storm the ancient seat of the gods, and when they defeat them, they will claim Olympus for their own.

Joining the Titans’ side are hundreds of demigods, some from Camp Half-Blood. Ignored, unclaimed, and disrespected by their godly parents for too long, they listened to Kronos’s promises of revenge and turned their backs on the Olympians. When the time to battle their former friends comes—and it will—they will not hesitate to raise arms and fight to the death.

Percy Jackson and his fellow camper Charles Beckendorf are not about to let any of that happen. When they learn Kronos is on his floating stronghold, the Princess Andromeda, they sneak aboard and set explosives of Greek fire. The plan is to get off the ship and trigger the detonators, then cheer as the explosion kills Kronos and all on board.

But in Percy’s world, nothing ever goes to plan. Kronos captures the demigods. Luckily, his men aren’t the brightest. They don’t realize that Beckendorf has readied the Greek fire. All he has to do is push a button on his watch. . . .

Beckendorf signals Percy to jump overboard. Then he detonates the bombs, blowing up the ship and sacrificing himself to stop Kronos. Except . . . Kronos survives. His army closes in on Manhattan. Soon the battle of the gods and the Titans will begin. And when it does, it will destroy the city and the people in it.

Desperate to find a way to defeat the Titan lord, Percy travels to Westport, Connecticut, to talk to May Castellan, Luke’s mother. Maybe something from Luke’s past will help him penetrate past Kronos to reach whatever remains of Luke’s essence. But May lost her mind years earlier when she tried to become the next Oracle of Delphi. It’s a dead end.

Dead is the first thing that comes to mind when Percy returns to Manhattan. All the people have collapsed where they stood. But they’re only sleeping, put down by Orpheus, the god of dreams, so they won’t interfere in the battle to come.

And come it does . . . with a vengeance. Monsters, Titans, Cyclopes, giants, and demigods launch a citywide attack. The air is thick with arrows, smoke, and projectiles heaved from catapults. Swords clash and slice. Magical explosions bring down bridges and buildings. A drakon rages and a pig flies (really).

The battle’s deciding moment comes when Annabeth stands before Kronos, unarmed and bleeding. She appeals to Luke, reminding him of a promise he once made to keep her safe. The last vestige of his humanity overpowers Kronos . . . but is he strong enough to break free of the Titan’s hold? Or will Kronos consume him once and for all and storm Olympus with his Titan horde? And if he does, will he find all the gods waiting for him? Or just one . . . the last Olympian?