At first glance, a black metal album of anguished contemplations about death and inevitability that opens with a nearly 19-minute song would seem impenetrable at best, but on Mammal, the second full-length offering from Irish experimenters Altar of Plagues, the whole thing somehow works. In the way that all great black metal albums are, Mammal isn't alienating so much as it is isolating, making the album not only a collection of songs, but a space in which to ruminate carefully over them. By putting the listener into the appropriate headspace, Altar of Plagues are able to exert total control over the listening experience, taking listeners on a journey that, through all of the brittle production and icy, unforgiving atmosphere, is remarkably thoughtful, introspective, and visceral. This feeling really shines through in how surprisingly dynamic the record is. The songs don't just pummel listeners into submission with their intensity, but are instead more tidal, ebbing and flowing between feverish, blastbeat-laden outbursts and quieter, more expansive passages. Combined with the spaciousness of the production, this push-and-pull approach speaks to a certain inevitability, as if to say that no matter how hard they fight, the songs always have to slow down. As an album, Mammal asks a lot of the listener. It presents an uncomfortable space in which to consider an uncomfortable subject with an austerity that will dispel any notions of black metal being only concerned with the evil or the brutal. Altar of Plagues have created something that's challenging and haunting, and those who are willing to put in the time will find an album that's not just effective, but affective.