Wandering the dark, dry warrens beneath the Colony with his best friend, Chester, and his brother, Cal, boy archaeologist Will Burrows stumbles across the Styx's dastardly plan to enslave all Topsoilers by unleashing Dominion-a debilitating viral weapon. But before Will can put a stop to the plot, he's got to evade not only a couple of killer Rebecca clones but also a bunch of sharpshooting bounty hunters led by none other than his long-lost biological mother! Where is Will's dad? What's at the bottom of the mysterious Pore? How much lower can they go?!