Behind enemy lines, new soldiers will emerge, and unexpected heroes will rise.

Ava is a prisoner. And she is not the only rebel held hostage at ISAN's secret compound. As she plans an escape, the lives of the rebel prisoners are in her hands, along with those she thought were dead.

Rhett and his team desperately search for Ava while one of the Remnant Council joins forces with another network looking for the creator of the Helix serum. And time is running out. Mr. Novak has been secretly creating an army called CODE, and what he plans for Ava will mean a permanent end to the rebels—and her.