OK, so this isn't the most encouraging promo photo. But the scowly gray-haired fellow with the hat—the one who looks like he's been hit in the face with Alice Cooper—is in fact Thomas Gabriel Fischer, better known in the world of extreme metal as Tom G. Warrior of the seminal bands Hellhammer and Celtic Frost. (If those names don't ring a bell, I have a book to recommend.) His post-Celtic Frost group, Triptykon, has embarked on its first stateside tour, traveling with Norwegian black-metal crew 1349 and locals Yakuza (who've already made fans of Fischer and company on the trip). They play Bottom Lounge on Saturday night. Triptykon are second of three—they're alternating with 1349 in the headlining slot—and Yakuza open.

Eparistera Daimones (Prowling Death), Triptykon's only album so far, came out in March, and at the end of October they'll release an EP called Shatter that includes two live covers of Celtic Frost songs. Aesthetically they pick up right where the revivified Celtic Frost left off in 2008—their sound is simultaneously cavernous and claustrophobic, like a huge lightless crypt, and while they sometimes break into a vicious, relentless gallop that recalls the black- and thrash-metal elements of Hellhammer and early CF, much of Eparistera Daimones is far slower, moving with a deliberate, evil majesty.

The faster stuff may get more fans riled up, but the down-tempo songs make better showcases for Fischer's distinctive guitar tone: dark, congested, and thick as wet cement, it's the perfect complement to his furiously melodramatic lyrics and scenery-chewing vocals. Nobody can sing "I shall feast on your decay" quite like he does.

Concerning the faster stuff, though, one friendly word of warning: If you hear the opening riff of this song, find something that's bolted to the ground and hang onto it. Folks are about to get rambunctious.