Chrysalis

You may be looking for Chrysalis (station).

Chrysalis by Brendan Reichs is the third book in the Project Nemesis series."'The test subjects of Project Nemesis have managed to survive the first two phases of the Program—and each other. Now they've emerged at the dawn of a new era on Earth, into a Fire Lake valley that's full of chaotic dangers and challenges, with death—real death, final death—lurking around every corner. The battle to stay alive in this broken world should force Min, Noah, Tack, and the others to work as a team, but old feuds die hard, and the brutality of earlier Program phases cannot be forgotten. ""Burying the past is never easy, and when the classmates discover that they may not be alone on the planet after all, they'll have to decide if they're going to stand together . . . or die alone, one by one.'" AMAZON 

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