Faced with choosing between saving Milo's life and embracing her destiny, Libby Sparks knows there is only one answer. Become the Destroyer. She's about to learn that accepting her fate is only the first step in figuring out what being the Destroyer truly means. Libby must rein in and develop her talents, plan the rescue her captive army of Ciphers from the hands of Guardians, and not lose herself along the way. Rescuing the Ciphers is already dangerous enough, but everything becomes even more precarious when Cipher hunter, Braden, pushes his way into Libby's life. While the strange connection they share frightens her, it pushes her to trust him despite her better judgment, putting her relationship with Milo to the test. If she's wrong about Braden's motives, everyone involved in the Cipher rescue may pay the ultimate price for her mistake.