A new prophecy leads to a dangerous quest. When Percy receives an urgent distress call from Grover, he immediately prepares for battle. He knows he'll need his powerful demigod allies, Annabeth and Thalia, at his side; his trusty bronze sword, Riptide; and...a ride from his mom. The demigods race to the rescue, only to find that Grover has made an important discovery: two new powerful half-bloods, whose parentage is unknown. But that's not all that...

The long-awaited prophecy surrounding Percy Jackson's sixteenth birthday unfolds as he leads an army of young demigods to stop Kronos in his advance on New York City, while the Olympians struggle to contain the rampaging monster, Typhon.

All year the half-bloods have been preparing for battle against the Titans, knowing the odds of victory are grim. Krono's army is stronger than ever, and with every god and half-blood he recruits, the evil Titan's power only grows. While the Olympians struggle to contain the rampaging monster Typhon, Kronos begins his advance on New York City, where Mount Olympus stands virtually unguarded. Now it's up to Percy Jackson and an army of young demigods...

In this Percy Jackson mini adventure first published in The Demigod Files, the goddess Persephone summons Percy, Thalia, and Nico to the Underworld to retrieve Hades's powerful sword before it falls into the wrong hands. Easier said than done in a realm full of daimons, ghosts, and monsters. Not to mention Iapetos-brother of the powerful Titan lord, Kronos. Will the demigods manage to find and return the sword before it's too late? Includes an excerpt...