From the acclaimed author of the Earthseed series, two immortals chase each other across continents and centuries, binding their fates together and changing the destiny of the human race.  Blake Maslin is traveling with his teenage twin daughters through an alternate America marked by volatile class warfare when their car is ambushed. Their attackers appear sickly yet possess inhuman strength, and they transport Blake's family to an isolated compound. There, the three captives discover that the compound's residents have a highly contagious alien disease that has mutated their DNA to make them powerful, dangerous, and compelled to infect others.  If Blake and his daughters do not escape, they will be infected with a virus that will either kill them outright or transform them into outcasts whose very existence is a threat to the world around them.   In the following hours, Blake and his daughters must make a vital choice: risk everything to escape and warn the rest of the world, or accept their new reality—as well as the uncertain fate of the human race.