One-man band The Ruins Of Beverast has been producing some of post-Millennial black metal's most interesting and atmospheric offerings since 2004's Unlock the Shrines, so you'd be forgiven for thinking that album number four will continue along that path. Moving away slightly from the progressive aspirations of 2009's Foulest Semen of a Sheltered Elite, Alexander von Meilenwald has here embraced the doom elements that popped up briefly on previous albums. And it fits seamlessly with the concept, a compellingly bleak narrative from the viewpoint of the author of the Malleus Maleficarum, the tome used in many 'secular' courts in the late 15th and early 16th century to persecute, torture and execute women accused of witchcraft. As a look into Kramer's mental state, Blood Vaults, or to give it its alternative Latin title, Cryptae Sanguinum - Evangelium Flagrans Henrici Institoris, is gripping...

As an atmospheric black metal album, however, it drags - not, perhaps, surprising, given that it is an album with an alternative Latin title! As a depiction of a mad mind, so enveloping is this portrayal that it's not really enough to dip in and out of it – you have to soak yourself in Blood Vaults for many listens, become familiar with its twists and turns and become accustomed to and forgiving of its lengthy, dirge-like tracks. Listening to it can even be a chore, more so than most albums of the weird black/doom subgenre. Beginning with growls and swirling keyboards, Apologia is the introduction to the tome, and the grinding buzz of a riff that opens first track proper Daemon the explanation of why it is necessary. It immediately sets an unrelentingly dark tone that is present throughout the album. But unless you're sat following the lyrics, or have an in-depth knowledge of the source material, then a lot of this will wash over you. Albums that you have to research to understand will always have an immediate barrier to entry for those of us who don't spend our limited time on this earth researching the darkest times in humanity's history (I admit it; I haven't read the Malleus Maleficarum and am unlikely to ever do so). Malefica's echoing vocals, church organs and slow doom riffs are undeniably mighty, for example, but if you want to be moved by this, for it to be the sort of semi-religious experience that the most ardent devotees of the band claim it to be, then you'd better do some reading...

Yet the mark of quality here is that even with bearing all that in mind, Blood Vaults is still very good. Whatever your pre-existing notions of witch-hunts or even what The Ruins of Beverast should sound like, there's no denying von Meilenwald's talent at creating atmosphere. Which is fortunate, as it's on atmosphere that this succeeds or fails – the crunching darkness of Ornaments on Malice is a perfect merger between black metal and Triptykon-esque doom, a shuffling creature of fear that finds the squeal of feedback (rightfully) as haunting as the blastbeat. The frequent Latin chants and ghostly choirs are a perennially effective tool, but in von Meilenwald's hands, dripped here and there like effluent slime, they become something quite otherworldly and eerie in a Lovecraftian sense. That L-word isn't as out-of-place as you might think for a tale grounded in such grim reality as this; take the thirteen-minute Spires, The Wailing City as an example, opening with surprisingly clean guitar strokes and gradually introducing that buzzing riff and distorted vocals, building up to a doom epic. It's the construction of a tale, laid out in the lyrics, of a woman being accused of witchcraft and building up to a hysterical belief in the supernatural matched by Lovecraft's feverish writings. The imagined monsters are just as horrific and otherworldly, the level of puritanical outrage at this filthy invasion into an otherwise pure existence the same.

It's not fully consistent, however. The moment of Shamanical invocation of A Failed Exorcism is simply bizarre (if a clever metaphor for exorcism), sticking out from the surrounding cacophonous black metal like a sore thumb. Trial and Ordeal's mini-tracks (at only three minutes-odd each as opposed to the usual eight plus) feel out of place even if their place in the story, and execution with suitably cheesy female vocals for the accused, is exact. And the grand finale to all this, Monument, is not a wild-eyed, raging lunatic shrieking hatred at a presumably innocent woman being burnt at the stake as I was expecting, but a slow, quiet piece addressing the accused with backing Latin chanting, ending on a whimper rather than a bang. The lack of payoff really damages the album, although you do find yourself returning to it, still looking for the sheer depth to which you feel entitled. Blood Vaults is ultimately neither a good or a bad album, then, but a frustrating album, the sort of declared 'masterpiece' that will still be argued about for years and will get places on year-end lists as much to wind people up as to genuinely proclaim its quality. Few would deny that Alexander von Meilenwald has done and will do better. Yet a misfire from one of black metal's most intriguing voices is still a fascinating experience, and Blood Vaults will likely captivate you even with its flaws.