Musician Aaron Turner started working on new material that would eventually become Sumac with the intention of writing some of the heaviest music he'd ever created. After creating the skeletons of a handful of songs, he turned to Kurt Ballou of Converge and asked if he knew of a drummer that would fit well with the music he wrote. Ballou, who worked with the Canadian crust-punk band Baptists in April 2014 to record their second studio album Bloodmines, recommended Baptists drummer Nick Yacyshyn. Turner and Yacyshyn jammed together and clicked, and Yacyshyn commented that the music they were working on was, "a pretty dense, heavy experience and kind of out there, I'd say. I've never been in a band that sounds like this." Even though both members were a part of other projects at the time, Turner announced that ]Sumac would attempt to be a full-time band that would continue to write, record and tour, instead of being just a side band.

Sumac will release its six-song debut album titled The Deal on February 17, 2015 through Profound Lore Records with Turner's own SIGE Records handling the vinyl pressing. Turner invited Brian Cook (Russian Circles, ,ex-Botch, ex-These Arms Are Snakes) to be a session bassist for The Deal, and also to be "an auxiliary/intermittent member for live performances when possible." The album was recorded by Mell Dettmer (Earth, Sunn O)))) in Seattle, Washington and mastered by Ballou in Salem, Massachusetts. To promote the album, Sumac released the tracks "Thorn In The Lion's Paw" and "Blight's End Angel" for online streaming prior to its release. The band will embark on a short North American tour in support of The Deal in March 2015.