Foundling Fever Crumb has been raised as an engineer although females in the future London, England, are not believed capable of rational thought, but at age fourteen she leaves her sheltered world and begins to learn startling truths about her past while facing danger in the present.

When she returns home after two years, Fever finds that her Scriven mother's creation, New London, the city on wheels, is nearly complete and ready to fight the nomad tribes of Britain--and Fever must journey to the north to find the ancient birthplace of the Scriven mutants and solve the mystery of her own past.