Calamity: A Reckoners Novel by Brandon Sanderson

Calamity is the third and final novel in Brandon Sanderson's The Reckoners series, which presents a dystopian world where superheroes, known as Epics, have used their powers for evil instead of good. The novel follows the main protagonist, David Charleston, and the remaining members of the Reckoners as they try to save their former leader, Prof, who has succumbed to the dark influence of his own Epic powers.