San Francisco's Fallujah pushed their own progressive deathcore envelope further than their blackened crackle on 2011's excellent The Harvest Wombs.

They moved toward a bolder, more sonically imaginative extreme, engaging technical death metal without sacrificing the nasty aggression that made that record memorable.

The Flesh Prevails doesn't just build on the promise of those records, but follows directly on what was created on the Nomadic EP, surpassing both in vision and execution.

They simultaneously deliver more gristly meat during the first half, while shifting gears in the second, adding more ambitious sonic atmospherics, while keeping most of the aggression.

Guest backing vocals from dark pop singer Roniit Alkayam on various cuts add to the set's complexity and appeal.

Zach Ohren's engineering achieves an entirely new level here -- even by his lofty standards.

Opener "Starlit Path" is full of melodic, riff-like labyrinthine twists and turns with Robert Morey's dissonant bass, Andrew Baird's in-the-red (literally) blastbeat drums and Scott Carstairs' angular leads are engaged in mortal combat with Alex Hoffman's growling vocals, and new guitarist Brain James' signature machine-gun rhythm guitar assault.

This is underscored further on the taut frenzy that is "Carved from Stone" that is so close to coming off the rails, it screeches with the sound of metal grinding on metal.

On the title track, shimmering synth, reverb, and ambient layers introduce a syncopated yet insistent drum pattern, a wailing guitar solo, and a wide-angle dynamic where technical six-string interludes contrast with the nearly jazzy rhythm section.

The far more complex bassline and layered clean backing vocals on "Leviathan" still build to a shattering climax.

The lone instrumental, "Alone with You," is an electronics lush, lithe, and languid, much as "Silent" was on Nomadic.

"Allure" is nearly majestic in its martial aggression, albeit underscored by a complex melody line that gives way to an explosive, balls-out, double-kickdrum sprint.

"Sapphire" is a collision of all things hideous and beautiful, with cacophonous guitar interplay between James' and Carstairs' bruising, vanguard lyricism.

Add a squalling bassline, skull-crushing drums, bleeding-edge screaming, and you have an epic.

The Flesh Prevails is a mammoth leap forward for Fallujah, but perhaps even a complete game changer for metal.