The Hero of Ages

The Hero of Ages is a fantasy novel by Brandon Sanderson and the third book of the Mistborn trilogy, published in 2008. It is described by its publisher as the third act of a three-act structure rather than simply a third volume.

The premise rests on the discovery of a mistake. The heroes understand that what they had been treating as the central threat was not the true danger, so the book has to run two problems at once: the world falling apart in visible ways, and the slower revelation about why it is falling apart. Vin's freeing of Ruin from a millennium-long imprisonment is the event that has to be understood before it can be answered.

The physical situation is described in agricultural terms, with ash burying crops and mists becoming lethal, which is unusual for epic fantasy in that the end of the world is measured by whether people can eat. Sanderson's publisher notes that while the first Mistborn book overturned the usual fantasy narrative, this volume returns to some of the standard devices, which is one reason the trilogy is often read as a study of the form as well as a story.