Hailing from Richmond, Virginia and putting out the sort of thunderous, titanic doom that makes your average sludge unit sound like stoner rock, Inter Arma throw all sorts of genres into their particular mix, not least a hefty dose of black and death metal to give the resulting sludge a solid foundation of extremity. This is immediately obvious on fourth album Sulphur English, beginning with the ominous noisy ambience of Bumgardner (a tribute for Bill Bumgardner of Lord Mantis and Indian, a friend of the band who committed suicide in 2016) and soon exploding into rattling speed on first track proper A Waxen Sea, a twisted doom and death metal amalgamation that slows here and there for moments of grim-faced introspection before returning to the dash. Vocalist Mike Paparo has the sort of dry grunt more suited to death than sludge, his bellows and occasional shrieks echoing atop the technical but rambling guitars of Steven Russell and Trey Dalton, not to mention the clattering battery of drummer TJ Childers. It makes for an intense whole, almost overwhelming on initial listens even if you're used to the style and yet as an album Sulphur English is more than rewarding.

For one, it's an extraordinarily easy album to listen to, tracks flowing well and drawing the listener in (and giving a hint of why this album has received mainstream praise from the likes of Pitchfork) despite the obvious heaviness that owes as much to cavernous death metal as it does the sludge genre as laid down by the likes of Eyehategod and Neurosis. As heavy as any particular moment may be, it's easy to be hypnotised and drawn into the morass, like staring into the heart of a raging fire - that cover art particularly fitting. You can feel the sheer heat given off from the likes of Citadel, intense blasts of anger leaping out at you even with the shifts into slower tempos as the band draw out the impact of each riff or drum hit. And like the best doom Inter Arma are terrific at riffs, making them memorable and almost catchy between little touches that shouldn't work for this kind of music but do, such as the way the aforementioned Citadel gives itself up to eerie guitar soloing around the centre half before resuming the punishing sludge bombardment, the second half like some demented other-universe Morbid Angel where they turned into a doom band after Domination.

The truth is that as much as Inter Arma are pigeon-holed as a sludge/post-metal band, they're something of a unique entity, not truly in the Neurosis realm nor belonging to death metal. The martial intensity of Howling Lands, shrieks escaping between the clean singing like bursts of lava as the tribal drums pound relentlessly, is probably the closest thing present but it's still laced with the band's identity, ending on howling feedback and leading seamlessly into the acoustic opening to Stillness. Really, practically any track here could bear close examination, the nine minute Stillness itself a neofolk-esque invocation led by some terrific clean vocals and some Pink Floyd-esque psychedelic guitar playing that turns it into a Morricone-esque soundscape around the midpoint, droning metal guitars turning the heat up thereafter and making an already great piece of music into something close to genius. The following sub-two minute Observances of the Path is a necessary piano-led breather as you come down from the high before a flamboyant drum opening to The Atavist's Meridian launches you into the aether again.

On an album so rich with excellence this is a personal pick for peak performance, building up to a blackened frenzy with a complex wall of guitar noise descending like a fog through which the remarkably good technical drumming comes clearly - usual collaborator Mikey Allred having done a ridiculously good job with the mix. Around the centre it descends into atmo-sludge meandering but remains gripping nonetheless, woozy singing coming through the fog as the drumming holds the song together like a spine. And then the singing turns harsher and madness strikes, the riffs growing heavier, the intensity of the build turning almost physical as the band drag you to the top of the mountain... and then allow uneasy rest at the summit as the keyboard-dominated opening of Blood on the Lupines turns heaviness to terrible beauty. And as for the closing title track, initially another drumming fetishist's wet dream, it takes a turn towards funeral doom terrain around five minutes in as the riffs turn slower and indulge in more feedback, brief moments of scurrying speed here and there growing longer and more deranged as the track progresses until the blastbeating drums are almost entirely separated from the doomy guitar tones, a ritualistic beating that somehow seems entirely fitting and that closes the album perfectly. How we MetalReviews-ers have missed the chance to cover three previous albums from this project can't be easily explained, but Sulphur English is the sound of an excellent band at the height of its power and is, without doubt, the sludge event of the year.