Calamity

Calamity is the third and last book in Brandon Sanderson's Reckoners series, set in a world where a mysterious event in the sky gave ordinary people extraordinary powers. These people, called Epics, have used their abilities to rule and terrorize everyone else, and David has been bound up in their cruelty ever since it began.

The stakes become personal this time. Regalia, one of the Epics, has turned Prof, the leader of the Reckoners and David's closest ally, into a deadly enemy. The conventional wisdom is that once someone surrenders to their Epic powers, there is no way back.

David is not ready to accept that. Megan showed him that Epics are not necessarily lost for good, and he is stubborn enough to act on it. To win his friend back, he will have to confront the most powerful High Epic of all, knowing he may not survive it.

This is the concluding volume, so it is best read after Steelheart and Firefight, the first two books in the series.