The human race is fighting back. Hundreds of miles apart, Elizabeth and Thomas continue to deal with the aftermath of a global catastrophe, as the Mass Extinction Event series enters its fourth volume. For Elizabeth, the sudden appearance of armed soldiers leads to an unlikely reunion. As she learns more about plans to save human civilization, however, she comes to realize that difficult decisions have to be made. Meanwhile, Thomas learns the truth about the mysterious group living close to Lake Erie, and a terrifying ordeal in the forest leaves him facing the prospect of his own imminent death. In the first three volumes of Mass Extinction Event, Elizabeth and Thomas had to deal with the slow death of humanity. Now they're about to come face to face with other survivors who have very different ideas about the human race's next step.