At a time when pop singles are ruling the charts, heady metal rockers Mastodon have put all their energy behind a full-length concept album, best listened to in one sitting.

With pounding drums, swirling guitars, and harrowing lyrics, Emperor of Sand tells the story of a desert wanderer, attempting to escape a death sentence. “It’s about going through cancer, going through chemotherapy and all the things associated with that. I didn’t want to be literal about it. But it’s all in there.” drummer Brann Dailor told Rolling Stone. When the concept album’s traveler ultimately dies in order to be saved, the metaphor become clear.