More than six months after the eruption of the Yellowstone supervolcano, Alex and Darla retrace their steps to Iowa hoping to find Alex's parents and bring them to the tenuous safety of Illinois, but the journey is ever more perilous as the remaining communities fight to the death for food and power.

We have waited generations for you... Syd Chambers knows that there's life on other planets because he's descended from it. His father was from a distant world called Denza and has been missing--presumed dead--for years. When Syd discovers a device his father left behind that shows not only that he's alive, but where he is, Syd must set out on a mission of his own. But along the way, he discovers a deadly, unbearable secret that could destroy Denza,...