16-year-old Elliot lives in a group home, where he has long been bullied and ignored by his classmates, earning him the nickname "the Invisible Mouse." After an accidental encounter, he gets caught up in a conflict between two rival werewolf gangs—the Blue Moon and the Black Thorns—and is forced to become a double agent, spying on Kai and his friends. However, Kai and his companions don't hurt him; instead, they offer him warmth and protection. As they spend more time together, Elliot discovers that Kai and the others are werewolves, and is even more shocked to learn that he is Kai's fated mate. After going through threats, kidnapping, and gang warfare, Elliot is formally accepted into the Blue Moon pack, and finally, during a full-moon ceremony, he enters into a mating bond with Kai—completing his transformation from an invisible, unwanted "mouse" into a beloved member of a family where he truly belongs.
