It's a given that Eminem fell off. Like totally fucked it all up, got to the point where he retired and the best the world could manage was a tired shrug. He got bored, ran out of things to say, swapped his creativity for formula, became as boring as he felt bored. For all his toying with theatrical imagery, the records became gradually less playful, cartoon animations of everyday traumas swapped for palid retreads and tediously literal defensive whingings from a life most of his audience couldn't relate to. Even the title of his last album, 2004's listless Encore, screamed 'nothing new'. Worse, listening to the album it was easy to forget there was once more to his appeal than prurience, easy to assume once our curiosity over his personal life had been sated he'd have nothing left to give.

Crucially, it seemed he felt the same way, the key moment on Encore being towards the end of 'Rain Man' where he bleats a hollow boast "I ain't even got to make sense / I just did a whole song and I didn't say shit". Interviews to promote the following year's Curtain Call greatest hits compilation showed him no closer to solving his creative dilemma, wondering aloud whether his retirement as an MC would be permanent.

When the lead singles from Relapse limped into view this year it was tempting to wish it had been. First up 'Crack A Bottle' offered a grim faux sex party vibe akin to Dr Dre's creepy 'Bad Intentions', then 'We Made You' co-opted Jessica Simpson, recycling the celeb baiting antics of 'The Real Slim Shady' to no effect at all. Both seemed cut from the same materials as Encore or, worse yet, the type of cynical garbage 50 Cent has been churning out the last couple of years.

Thankfully they're as bad as Relapse gets. Though in a sense representative of the album, the torpor is misleading. In real life, in his five years away he's been through stardom, addiction, depression, rehab, relapse, and finally a year of apparently contented sobriety. At this point it'd be unreasonable to expect the famished, exhilarating desperation of The Slim Shady LP but it's a relief to find him audibly engaged, attempting to compete with himself. Take the opening stretch, a near flawless run through serial killing (in '3am', 'Same Song And Dance'), paedophilic ass rape (in 'Insane') and his mother serving him paint thinner and Valium for dinner (in 'My Mom'). Old subjects are pushed into new levels of unreal repugnance, further away from realism than ever before, an obscene panto.

It's a sequence which showcases well his knack for disjointed storytelling and easy elastic phrasing, switching up accents and flows, turning hairpin verbal bends with satisfied ease. 'Bagpipes From Baghdad' is typical, the opening ad libs coming on first like Sesame Street's count then briefly a mid-Atlantic Jimmy Nail, before switching back to Slim Shady for a romp through Mariah Carey's wine cellar, the sex lives of conjoined twins and namedrops for Zapp, Eric Clapton, Shaft, Frank Zappa, and crunk. Musically it's paced to match, trumpets parping, those titular bagpipes whining, and fairground organs pumping dramatically, all exaggerated like a schlock horror soundtrack.

Then it all goes a little wonky, starting with 'We Made You' then through a second half dotted with awkward party exercises ('Must Be The Ganja', 'Crack A Bottle') and mawkish self-pitying confessionals ('Beautiful'). A smattering of naff rockisms doesn't help either ('Stay Wide Awake', 'Beautiful') Occasionally the more straightforward material works, especially 'Deja Vu', a minor key acoustic guitar ramble with surprising country undercurrents, pulling apart the assorted uncomfortable fuckeries of his addicted psyche.

But however fine, such a moment can only pale beside closer 'Underground', a reprise and culmination of the hyperactive freeform theatrics that opened up the album. Heralded by the sound of thunder, a choir rides the storming stutter of a beat, warning "There's nowhere to run to now! Don't look for me! I'm underground!" And then Shady goes wild, throwing lesbians in wet cement, jacking off to a hockey mask, piss sipping and jumping out the toilet when you pee. There's still the suspicion nothing has been resolved since Encore, that he's still not really saying shit. It's just now he's learned how to do it with the conviction of old, so a line like "Hit a fag with onions / and split a bag of bunions" sounds more a hardcore philosopher's threat than the blathered dribble of a strung-out fool. He's learned how to act, to the point where his claim to be "the fucking antichrist" is plausible 'cos you can't help but will it so. Much as you'd like to rise above, hating him is too much harmless fun,

And that's where Relapse triumphs, not in presenting a flawless body of work but in making Eminem interesting again. He's timed his comeback well. Long enough to raise expectations but not so long they get too high, just the right distance to make this a welcome return and give hope for the sequel, Relapse 2 due at the end of this year. Let's just hope next time he doesn't invite Jessica Simpson.