Nyx is an organization-with bases all around the globe-tasked with training young girls and boys to become the most elite trained killers in the world. Starting their training at the age of six, they have to prove themselves skillful enough to survive to graduation at the age of twenty-two. As the youngest captain in Nyx history, Briar is faced with impossible trials. Over the years she has been tested to the highest expectations among the Initiative. She is expected to enforce the rules and keep her team alive throughout the upcoming exams and missions. When their most recent team exam ends with lives at risk, Briar is willing to bend the rules to keep the one she loves from ever slipping away. Though, an unexpected shift in orders from her director causes Briar to have to make a decision that could greatly affect her relationship, her training and her career.