Mastodon also released an EP titled "Cold Dark Place" on September 22 of the same year. It was a four-song EP, featuring three songs recorded during the "Once More 'Round the Sun" sessions, and one track recorded during the "Emperor of Sand" sessions. The first single for the EP, "Toe to Toes" was released on September 1, 2017. Brent Hinds stated that the inspiration behind some of the songs recorded for "Cold Dark Place", which he wrote, were inspired by a nasty breakup that he had endured. Describing the sound of the record, Hinds stated that "I wrote some pretty dark, beautiful, spooky, funky, ethereal, melancholy music, which also sounds like the Bee Gees a little bit." On December 1, the band released a revised version of the 12-part "The Making of "Emperor of Sand"" documentary via their official YouTube channel. Mastodon were announced to be on a co-headlining Summer 2018 Tour with Primus spanning across North America lasting from May to July.