Book Burner, the fifth full-length from Richmond, VA's grindcore mainstays Pig Destroyer, might lack the crystal-clear production of its predecessor, 2007's Phantom Limb, but that actually works in its favor. The raw sound displayed here immediately calls to mind the group's early work, particularly career high point Prowler in the Yard, and as such stands as their most focused, and altogether most intense work since then.

The 19 furious tracks spread across Book Burner's 31-minute running time deliver exactly what fans have come to expect from the group: J.R. Hayes' brutal, larynx-shredding vocals screeched and belched over Scott Hull's brutal, yet simultaneously incredibly catchy riffs accompanied by absolutely mind-boggling drum work (courtesy of new member Adam Jarvis, of Misery Index fame) in short and sweet increments. Time changes abound; just as soon as the group fall into a groove they're back to pummeling the listener with something new.

Pig Destroyer's brand of extreme metal demands multiple listens in order to decipher the nuances that make each track unique, as it can come off as a bit of a blur on first listen. Once this is achieved however, the differences are astonishing. "The Diplomat," featuring guest vocals from Misery Index's Jason Netherton, is a mid-paced (relatively, as it's still faster than most bands' fastest material) sludge stomper, deeply indebted to bands like Eyehategod, that also prominently features a riff surprisingly reminiscent of Chimaira's "The Dehumanzing Process." Even sludgier album closer "Permanent Funeral" surpasses the four-minute mark. In grindcore terms, that's "Stairway to Heaven"-esque excess. This versatility has allowed the group to release splits with everyone from Orchid to Isis.

While Pig Destroyer's sound displays several traditional heavy metal hallmarks, notably Scott Hull's Kerry King-influenced riffs and some Zakk Wylde-style pinch harmonics, the group's grindcore attack is firmly rooted in hardcore punk. This is evidenced by the accompanying bonus EP, which finds them covering classics from the likes of Black Flag, the Misfits, Angry Samoans, Negative Approach, Circle Jerks and Minor Threat. The group stay surprisingly close to the source material on these tracks, other than some decorative blast beats. It's interesting to hear Hayes use a more traditional hardcore bark in place of his trademark growls and shrieks. If you're going to plunk down the bucks for Book Burner, you might as well spend a few more and grab the deluxe edition for these tracks.

Book Burner might not be the finest grindcore release of 2012 (that prize goes to their peers in Cattle Decapitation, who took the genre down some interesting new avenues with Monolith of Inhumanity), but it's a good old fashioned blast of aggression from one the genre's most reliable (if not prolific) acts. Fans won't be disappointed.