Orpheus Collar

When Apophis, the chaos snake, threatens to plunge the world into eternal darkness, siblings Carter and Sadie Kane plan to use an ancient spell to destroy the snake, but first must rely on the murderous ghost of a powerful magician.

"Carter and Sadie, offspring of the brilliant Egyptologist Dr. Julius Kane, embark on a worldwide search for the Book of Ra, but the House of Life and the gods of chaos are determined to stop them"--

When demonic cheerleaders invade his high school, Percy Jackson hurries to Camp Half Blood, from whence he and his demigod friends set out on a quest through the Labyrinth, while the war between the Olympians and the evil Titan lord Kronos draws near.

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...

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...