"Mythological monsters and gods of Mount Olympus seem to be walking out of the pages of twelve-year-old Percy Jackson's textbooks and into his life. And worse, he's angered a few of them. Zeus's master lightning bolt has been stolen, and Percy is the prime suspect. Now, he and his friends have just ten days to find a return Zeus's stolen property and bringpeace to a warring Mount Olympus."--

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...

All year the half-bloods have been preparing for battle against the Titans, knowing the odds of victory are grim. Kronos'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...