Scribe Kenton lives in the last human refuge, known to its inhabitants only as the City. All he has ever known is the omnipresent threat of the Bladesmen, the eternal foes who trapped the few remaining humans over a century ago. Now the City is running out of the only resource that can keep its enemies at bay. Kenton is sent out into the world with the City's most valiant defenders on a revolutionary aircraft on a desperate mission to find a weakness in the Bladesmen's defenses. Soon he discovers that it is only a matter of time until the City falls forever. Only the human mission on board the zeppelin Lord of the City can hope to find a way to save the last remnants of humanity before their time runs out.