Isis—once jokingly referred to as “Neur-Isis” for its early similarity to Neurosis—has come into its own over the past few years as one of the most challenging, complex, and uncompromising acts in metal. Its 2006 album, In The Absence Of Truth, found the band expanding its sound into something oceans-deep, with huge, gauzy swirls of background noise and ambient keyboards spreading the band’s formerly concentrated thunderstorm into a less tempestuous—but no less ominous—blanket of clouds. Vocalist Aaron Turner has always growled his way through his grad-school literature and philosophy references, but he’s grown as he began flirting with a wider range of dynamics—which feature well on Wavering Radiant, the formidable 2009 Isis album put out by the totally weird label Ipecac. The band recently announced the end of its dozen-year run, with a farewell tour that ends June 23 in Montreal (the site of Isis’ first show in 1997). Along the way, the group will also wrap up a new EP and compile "live audio and visual material for future releases."