Heavy Christian rock & roll is no longer anything really new.

But Christian metalcore that sounds this dark and angry is pretty unusual.

It should be said that the relationship between ZAO's music and the beliefs of its members has always been a bit ambiguous, and indeed there is little on this retrospective collection that would tip off the uninitiated listener as to the group's religious leanings.

"Free the Three" seems, in fact, to be a defense of three adolescent Satan-worshippers unjustly accused of a murder; other songs, such as the sonically brutal "Skin Like Winter" (which slyly juxtaposes wall-of-guitar roar and screaming vocals with jaunty handclaps) and the complex, episodic "Ravage Ritual" (which evokes I Against I-era Bad Brains) are harder to get a handle on, lyrically speaking.

With this type of music, it doesn't make much sense to criticize it for sounding all the same -- bluegrass all sounds the same, and so does John Dowland's consort music, but that doesn't mean there's anything wrong with those types of music.

That said, though, the yowling-cat vocals do start to get a bit old by the end of the album, and when you hear the actual melody that shows up on "Angel Without Wings" you may experience an almost tearful sense of relief.

Like David Thomas once said, this is the perfect thing for people who like this sort of thing.