Hundreds of years after a cataclysmic event destroyed civilization, mysterious young Hester Shaw emerges as the only one who can stop the city of London -- now a giant predator on wheels -- from devouring everything in its path. Feral and fiercely driven by the memory of her mother, Hester joins forces with Tom Natsworthy, an outcast from London, and Anna Fang, a dangerous outlaw with a bounty on her head.