OS hails from Budapest, Turkey. They specialize in a brutal form of Death Metal. Although they formed in 2014, they released their demo in 2017, aptly named "MMXVII." In 2020 they dropped their debut EP, "Prehuman Death Magic," followed by their first full-length, "Stationes Viae Mortis," the same year. On November 4, 2022, they issued their sophomore full-length, "Tehom," via Iron Bonehead Productions.

"Tehom" is Biblical Hebrew for "the deep." It is the primeval body of water from which human life would evolve. Oops, Biblical. Forgot. So, let's say "pre-creation" instead, but not necessarily the primordial soup that produced Tiktaalik or even the brackish tidepool of the Innsmouth variety.  To add an esoteric wrinkle, apparently the ancient Hebrews understood this sea to be "an unpersonified entity." So, there's that. Also, in Kabbalah studies it is known as one of the Infernal Habitations. Yeah, so great name for a Death Metal album, band, or your next cat.

All of this is relevant as this entire album sounds like it was recorded underwater. I know that seems like it would be awful, but by some sort of voodoo, this album sounds incredible. I have never heard an album that was so muted and yet at the same time so loud.

"Tehom" is bookended by short instrumentals. The first, "Opening," introduces the subaquatic theme with a vocal track that sounds like a drowned man trying to summon the Great Old Ones. "Abyss," the outro, sounds like Cthulhu waking up in the Mariana Trench at midnight. Nestled between those two monoliths of insanity are about 32 minutes of glorious down-tuned Death Metal packaged in four tracks. The first of those tracks is "Gaze," which in my estimation is the best of the album. It's staged across several movements, each just as guttural and nasty as the other, summing up to over seven minutes of Death Doom abuse.

Next up is "Submerge" which lives up to its title by engulfing the listener in an unrelenting, blast beat assault. The assault continues with "Inhale" which features a full-on break-as in all instruments just stop-and the vocalist starts reciting something like the Necronomicon, backwards in Ancient Sumerian. The final proper track, "Dissolve," gets back to Death Doom. The first minute sounds like an alternate universe version of the "Black Sabbath," but a much darker universe where black hole gravity targets Death Metal riffs making them impossibly heavy. All this, of course, picks up tempo without losing mass and carries on for the bulk of the track before it finally deconstructs, as the title would suggest, by the end.

Be warned, this is a headphones-must album-not earbuds, but over-the-ear complete immersion headphones. They will also come in handy for pooling the blood from your eardrums. "Tehom" deserves a straight 666, but we'll round up to a full round of sevens.