Boneshaker - Cherie Priest
Sixteen years ago, in 1863, the mad inventor Leviticus Blue used his Incredible Bone-Shaking Drill Engine to breach a pocket of poisonous gas beneath the city of Seattle - a gas capable of turning those who breathe it into flesh-eating zombies. Now a whole section of the city is walled off to keep the gas - and the zombies - trapped safely inside.
Living on the outskirts of this wall, Blue's widow, Briar Wilkes, and his son Ezekiel, struggle to escape the shadow of his legacy. But when Zeke finds his way under the wall to try and exonerate his father, Briar is forced to follow after in the hopes of protecting him from the horrors within - not all of them undead.
Cherie Priest's Boneshaker is the kind of cohesive blend of imaginative concepts that always leaves me in awe. Airship pirates, steampunk contaptions, drugs distilled from zombifying gases, family secrets and a hidden underworld of survivors - all these things are linked naturally together in a world that, while certainly beyond fantastic, is also entirely consistent and convincing. I read this from cover to cover in a few days, but I suspect it will linger with me for far longer than that.