It's been nearly four years since the last Mammoth Grinder full-length, "Extinction Of Humanity," was released via Relapse Records (CD) and Cyclopean Records (vinyl). "Underworlds" marks a peak at which Mammoth Grinder has sharpened and perfected their sound into a seething grind/death/thrash maelstrom of intense degree. Unrelenting in concentrated raw precision and focused power, "Underworlds" careens violently through 10 tracks with effortless versatility and the fixated songcraft expected of a band on their third record. Tracks like "Wraparound Eyes" with its Unleashed-style midsection or the short sharp shock of "Paragon Pusher" illustrate Mammoth Grinder's mastery over multiple variations of metal to assemble their own sound. Now available on vinyl.