After a secret prison hidden underneath the Wyoming countryside suffers an unexpected explosion, the nation's worst serial killers are once again at large. Former FBI profiler Bex is brought back into the fold alongside an elite team of soldiers, spies and special agents to help track down and recapture these deadly criminals before they kill again. Thrust into a world of intrigue and conspiracy, Bex must grapple with not only her own complex past, but also the enduring mystery of what was happening at this prison -- and who caused the explosion in the first place.