The Four Kings series is a collection of young adult fantasy novels that follows the journey of four brothers who seek to evade the dire consequences of an ancient prophecy that targets them. This prophecy poses a threat to some of the most powerful individuals in the world, who will stop at nothing to prevent it from being fulfilled, even if it means harming children before they have a chance to grow and become a danger. In fear for their safety, the mother of the Renn brothers trained them to keep their youngest brother a secret while they prepared to defend themselves against the world. When the eldest brother, Kai, leaves for training and the youngest brother, Kanai, finally emerges from hiding, the family begins to adapt to their new dynamics. However, their newfound visibility attracts the attention of someone who wants them dead. Now, the brothers find themselves fighting on multiple fronts to survive.