Diagnosed as a psychopath as a child and trained as an assassin at a secret CIA institute, Emma Garthright is not like other teens. But now Emma is faced with the one mission she isn't prepared for—making friends at an ordinary high school.

Sixteen-year-old Emma has spent most of her life at the remote Early Institute, a boarding school operating under the guise of helping children like Emma become better people. But the Early Institute's altruistic façade hides a darker motive—to turn its students into the deadliest teenage assassins the world has ever seen.

Taught to kill without question, Emma is tasked by her demanding headmaster with going undercover at Grover Cleveland High School. There, she must do the seemingly impossible—truly become a better person in order to win the trust of Grover Cleveland's most virtuous student, Susie Robinson, and help Susie gain the affections of her crush, Brayden. Susie is a straight-A teacher's pet, naturally suspicious of the manipulative and deceitful Emma, and the one person standing between the success or failure of Emma's mission to assassinate an international political figure. But is Emma really capable of changing? And why does it seem like Brayden is more interested in her than in Susie?

As the deadly teen's newfound freedom and friendships start to get in the way of her mission and the sinister truth behind the Early Institute begins to come to light, can Emma use her wits and lethal skills to save her friendship with Susie while keeping them both alive?