A great Traction City begins the chase with a smaller one, eager at the chance of fueling its starving engines. Resources on the Great Hunting Ground that once was Equestria have grown so scarce that mobile cities have begun to devour each other for much-needed supplies to survive, a practice known as Municipal Darwinism.
William, a unicorn and apprentice navigator, is tasked with discovering the motives of an approaching city to save his own. However, when a mysterious Sarah causes their airship to crash, Will and Sarah find themselves alone in the Out Country. As they trek back to the city, the sinister plans of Trottingham's leaders begins to unfold…

Artwork by Christian Bravery
Mortal Engines written by Philip Reeve