In a post-apocalyptic world ravaged by a catastrophic event known as the Sixty Minute War, humankind has adapted to a new way of life on moving cities. These massive mobile metropolises roam the earth, engaging in a survival of the fittest paradigm known as "Municipal Darwinism," where larger predator cities hunt and absorb smaller traction towns for resources. On one of these behemoth roving cities, the great traction city of London, a young apprentice historian named Tom Natsworthy encounters a mysterious, scarred woman named Hester Shaw. Hester harbors a deep-seated hatred for Thaddeus Valentine, London's revered Head of the Guild of Historians, and attempts to assassinate him, leading to a tumultuous chain of events.

The chaos of the failed assassination attempt causes Tom and Hester to be expelled from the moving city, forcing them to form an unlikely alliance in the perilous Outlands, the vast static remains of the world that predated the roving cities. Together, they discover a conspiracy that threatens the very existence of their world. With the dangers of the Outland and vengeful parties in pursuit, they embark on a quest across the desolate landscapes, encountering disparate societies, and uncovering the relics of the ancient world that hold the secrets to a power capable of changing the future of civilization.