THREE FRIENDS Jack McKinley and his friends defeated the Colossus of Rhodes, unearthed the treasures of the Hanging Gardens of Babylon, and recovered two of the seven lost Loculi - only to find they'd been betrayed by one of their own. TWO SIDES With Babylon in ruins, Marco on the Massa side, and long-held secrets coming unraveled, the kids don't know who to trust or where to turn. Their G7W powers are manifesting at a furious pace. They have no choice but to continue their quest, to the most terrifying of all the Wonders.ONE LIFE With lives in the balance, the kids rush to the next stop on their quest, the famed Mausoleum at Halicarnassus. Here they have to face down their own demons and engage an epic battle with the shadows of the dead. But when promises are broken and blood is spilled, the kids find themselves with nowhere left to turn.SEVEN WONDERSJoin Jack, Marco, Ally, and Cass in their quest to save the world and themselves in this third installment of the bestselling adventure series from master storyteller Peter Lerangis.