This is no longer just about the Marked kids, its about every person alive. Sienna and Theo escaped the Void, but they are not free of the Reeks. With the Void overrun by Reeks the wall that has kept them safe for years may soon fall. Already, Reeks are destroying villages, and there are not enough of them to keep up. He's here, he's alive. Jayla keeps reminding herself that Caspian escaped the horrors of the Void with his life, but the memories of what she saw threaten to destroy her. She's not weak, and these people need a leader, but she can't hide the truth from Cas or Em, and she doesn't know how to stop the panic. Gunner made a mistake; he trusted the wrong people all because he needed information. There is no way to make up for what he did, but if he stays by Vic's side maybe he'll have a chance to survive. He knows her friends will come for her, but will they kill him on sight? Genetic kids are going missing, not just...

She's always been good in fights. But can she kill to survive? Hunting artifacts while being hunted by deadly creatures that are impossible to outrun. That's what Sienna must do. The DEZ might have given her military training, but nothing could have prepared her for her new life in The Void. Sure, there are other Marked kids in this vast, dark place. But they're not her friends – they're competition. At least she has Theo. But where is Vic? Sienna knows her innocent friend will never survive in a place like this. She has to find her. Even if it means killing every Reek she can find. Meanwhile, Jayla is struggling to come to terms with the loss of Cas, while trying to learn what is behind the giant wall. More importantly, she must learn how to get there to keep her promise to the Marked kids. A promise she's so far failed. But the more she learns, the more she fears. If Sienna and Theo are going to live for more...