would record an eleventh studio album if Dark Roots of Earth did well. A week prior to the release of Dark Roots of Earth, Billy promised that Testament would not take "huge gaps" between albums anymore, and would "work hard and tour for two years or so," and try to release another album when they could. Hoglan had also said that he would "absolutely dig" to be a part of the writing of the next Testament album. On September 13, 2013, Billy told Rock Overdose that from January to April 2014, Testament would be writing and recording their eleventh studio album for a 2014 release. Testament released a live DVD/double album Dark Roots of Thrash on October 15, 2013. The release documents the band's sold-out headlining performance at the Paramount in Huntington, New York, in February 2013. In January 2014, bassist Greg Christian left Testament again, and was replaced by a returning Steve Di Giorgio. Christian has claimed that the reasons behind his departure were because of money disputes and differences with the band. When asked in an April 2015 interview about Testament's plans to begin recording their twelfth album, Peterson said that his "main goal" was to "get home [from tour] in June, finish it up and get in the studio by September." Billy also said that the band's goal was to have the album finished by Thanksgiving. Slovenian bassist Tilen Hudrap (Pestilence, Vicious Rumors, Paradox and Thraw) and Bay Area drummer Alex Bent (Arkaik, Dragonlord and Decrepit Birth, Battlecross) filled in for Di Giorgio and Hoglan respectively at the prestigious Canadian open-air festival Heavy Montreal in August 2015, which was attended by more than 70,000 spectators. In May 2016, Billy confirmed their twelfth album would be entitled Brotherhood of the Snake. Of the album's lyrical content, he commented, "The Brotherhood of the Snake was actually a society about 6,000 years ago that debarred all religions. It was just a fascinating topic that caught our eye and attention and spawned a lot of songs. We're going with that vibe. There will be some songs that deviate, but the majority will be around that and aliens and religion. Then I'll probably tap into my native heritage and write some songs about that. It's not just going to be one concept, but there is some interesting stuff that we're finding to write about." Brotherhood of the Snake was released on October