In 1890, a disease that turned sane men into ravenous werewolves swept through the United States like wildfire. On the brink of humanity's extinction, Nikola Tesla and a mysterious order of scientists known as the Tellurians revealed a bold plan: the uninfected would abandon the Earth's surface by rising up in floating salvation cities, iron and steel metropolises that carried tens of thousands of refugees above the savage apocalypse. The remnants of mankind huddled fearfully in the clouds, waiting for the werewolves to devour each other. Twenty years later, beasts still rule the world below and now only the salvation city of Wardenclyffe remains aloft. But a telluric deadzone has caught Wardenclyffe in its riptide, forcing it toward airspace where its miraculous machinery will no longer function. Elijah Kelly, an infected Thunder Train crewman exiled to the ground, ranges ahead of his beloved home, determined to keep it safe no matter the cost. Desperate to neutralize the deadzone before the flying city crashes, Eli discovers a brutal truth: humanity still exists on the ground, paying a terrible vampiric price for their survival. Faced with an impossible choice between sacrificing thousands of innocent lives or betraying the rebels fighting for their freedom against an oppressive regime, Eli is forced to rely on an unlikely ally lurking deep within his own blood, his only hope if he wishes to defy the inevitable.