EASTERN STRUMMING chimes in 'Undertow''s most perverted hour, reportedly an ode to opening yourself up to new possibilities. Via the metaphor of anal sex. Ouch!

HENRY ROLLINS steps in to provide spoken-word vocals in this spasming riffathon on the darkest recesses of depressive states. 'I will use my mistakes against you... there's no other choice' the muscleman threatens. Scary.

'HE HAD a lot to say, he had a lot of nothing to say' intones Keenan robotically on this industrial-edged lament. Possibly about Kurt Cobain. Or possibly not.

ON WHICH Tool get their 'evolution' on, portending with imagery of scabs, shedding skin and metamorphosis humanity's step up into a higher level of being. Whatever that may mean.

TOOL DON'T like it if you call them sell-outs, and this seething, spitting metal assault on all their 'fans' who do hits below the belt. Hey, nobody ever said Tool were nice.

'I CAN say what I want to, even if I'm not serious' wails Keenan to a juddering funk-metallic backdrop, providing a precious key with which to read all Tool's work.

SLOW AND droning, 'Jimmy' is a mystical, dreamy return to a troubled childhood in search of answers which often prove elusive. Touching and strangely beguiling.

POSSIBLY TOOL'S most epic moment, where they reach out in order to touch infinity, transcribing into music the impulse towards the divine within us all. 'Spiral out, keep going' sings Keenan, offering a path of hope and endless possibilities.

EXPANDING LED Zeppelin's already dirgy lament to almost double its original length, this is the sound of Tool paying tribute to one of their faves.

'CHOICES ALWAYS were a problem for you, what you need is someone strong to guide you... like me' croons Keenan as he mercilessly mocks the weakness behind the need for organised religion on this slow-burning anthem.

ARGUABLY TOOL'S darkest, most disturbing moment, a harrowing tale of infantile sexual abuse set to the sound of a deceptively charming metallic ditty. Notoriously features the line 'shit, blood and cum on my hands'.

SHOWCASING TOOL'S constant need to expand their sonic palette onstage, this percussion-heavy live re-interpretation of this song reveals them to be one of the most affecting and challenging live bands around.

'I KNOW the pieces fit cuz I watched them fall away' croons Keenan on this melancholy, sedated meditation upon human relationships that fracture and crumble. Fragility was never so delicately rendered.

TOOL'S BASS-DRIVEN breakthrough single (and fucked-up accompanying video) depicts a soul imprisoned in endless self-reproach. Though why Jesus won't 'fucking whistle' is still a mystery to all.

INDUSTRIAL NOISE and feeback introduce this lurching onward march of a song about pushing your boundaries, and those of others, by means of the gentle art of fisting. Naughty.

BLISTERING RIFFAGE and pounding drums usher in a meditation on human suffering in an unforgiving universe, as Keenan gives vent to shadowy paranoia and unsettling deja vu.

ALCHEMY, ASTROLOGY, industrial vocals and wobbly tightrope-walking riffage all encourage you on this epic number to let go of your grudges in order to stop dwelling in self-defeating darkness and fear. Inspirational.

SLOW, GRINDING and seemingly endless, this song's sonics perfectly mimic its message of patience and strength when dealing with situations that appear to offer suicide as the only way out. See, Tool are nice after all.

PRO-DRUG LEGALISATION rants from comedian Bill Hicks introduce this 14-minute psychedelic prog-odyssey and urge to expand your mind and worldview. No drugs, no your favourite music.

'LEARN TO swim' yells Keenan as advice to all the shallow LA posers upon whom he wishes apocalyptic earthquakes, rain and destruction in this epically intolerant masterpiece.