Two generations ago, Earth's richest citizens—the Hoarders—seized control of the planet's resources, retreated into their heavily guarded Enclaves, and left the rest of the population to fend for itself.

Until recently, when the Hoarders began to randomly Implant people with a new kind of microtechnology, capable of converting their unsuspecting hosts into violent and deadly automatons.

They also created the Trackers, mechanically and chemically enhanced creatures fanatically devoted to hunting down and killing anyone unlucky enough to have an Implant.

Amos Morgan and Aubrey Carter, together with a small band of fellow Runners, must unravel the mystery, racing against time before the Trackers discover them.

And before their own Implants change them into . . .

Something else.