Midnight Legion, Book Two: The World Reborn

From publisher blurb: More than four centuries have passed since the Devastation engulfed Earth. The species that remained were fused and reborn in the alchemy of atomic fire. Now their diverse descendants have claimed the planet. You are an agent of the Midnight Legion, tasked with preserving life and rebuilding civilization. Only one other agent remains, and she is somewhere ahead of you, racing for your last remaining base. Unless you can reach it before she does, she will seize the command center and use its ancient weapons to unleash a second Devastation. This time, if she succeeds, nothing will survive. Your chase will lead you to new creatures, lost technologies and possibly even the clues your adversary leaves behind. But beware—there are no established paths across this constantly shifting land, and nothing is what it seems.