So, you think "progressive metal" is an oxymoron along the lines of "military intelligence" or "smart bombs"? Then you haven't had your brain pan hammered by Tool.

"Aenema," the band's second full-length album, is a sonic landscape as intelligently and inventively constructed as, say, Pink Floyd's "The Wall." Yet it's as pulverizing and urgent as anything by Metallica, and as creepy, subversive and insidious as ... well, recall that "Star Trek" episode about alien bugs that infect humans by crawling into their ears and setting up shop in their gray matter, and you have a visual metaphor for how Tool works.

"Aenema" employs snippets of techno sounds, slithery grooves, carnival organ, a baby's crying, lonely piano and industrial metal noise that really sounds as if it were bred in some dank, Kafkaesque, German factory. To top if off, the album also is infected by a good deal of spacey, ambient interludes that almost would be at home on a New Age album.

But it's all used by Adam Jones merely to set up the slaughter of his guitar playing. Sonic scud-missiles, raging, grinding riffs, staccato blasts that sound like Godzilla with hiccups -- Jones unleashes them as lethally, as unflinchingly as one of those rifle-toting bags of testosterone who blow away exotic big game in those "caged hunts."

Vocalist Maynard James Keenan employs a similar modus operandi. Sure, at times he sounds anemic, even -- oddly -- like John Lennon. But that's only before the time-released capsules of venom explode in his voice as he vents lyrics of rage, existential angst and more than a bit of misanthropy. Yet he manages to be menacing without being goonish or cartoonishly satanic.
 

On "Eulogy," Keenan moves from a reedy mutter to a bellow: "Standing above the crowd, he had a voice that was strong and loud, and I swallowed his insight because I was so eager to identify with someone who would die for me ... Would you die for me? Don't you @#%*&@ lie! Get off your @#%*&@ cross!"
 

"Pushit" is a chilling bad-love song in which we don't know if the narrator is victim, executioner or both. "Down in the hole again, hands on my back again," Keenan sings over now ghostly, now harsh guitars. "Violence is my only friend. Remember that I love you, even as I blow your @#%*&@ throat away. It will end no other way."
 

The misanthropic title track sports a ranting Keenan who's ready, willing and eager to ride out the end of the world, the better to have the planet purged of "millions of dumbfounded *&#%$@": "Some say the end is near, some say we'll see armageddon soon. Certainly hope we will. I certainly could use a vacation from this *&@@%&#, three-ring circus sideshow."
 

Of course, Keenan's rants against "gun-toting, hip gangsta wannabes ... junkies ... dysfunctional, insecure actresses" and "these clones" never sound as if he's talking about me or thee.
 

Frankly speaking, Tool has hammered out a slab of metal that makes Metallica's latest, "Load," seem as puny as the soundtrack to a Disney World ride. Similarly, Tool makes such metal bands as Pantera and Slayer seem as sluggish and dull-witted as a lobotomized gorilla. "Prog metal' is an awesome tool in the hands of Tool.