"I think the time is perfect right now," says Gary "Genius/GZA" Grice. "Hip hop is missin' somethin' important - it's missin' a main element. And Wu-Tang are the ones to bring that element."

It's been 14 years since the Wu-Tang Clan took hip hop by the scruff of the neck and kicked new life into a stagnating genre. They arrived just as the first flush of gangsta superstars helped shift rap's centre of gravity from its New York birthplace to the barbecues, swap meets and low-rider cars of sun-kissed Los Angeles, a city on the opposite coast with its own distinct style.

Today, the rap game is on the cusp of a similarly uncertain future. People agonize about rap and its integrity and beliefs, record sales are down, panic is setting in, and the audience is confused. Where can a genre in turmoil turn to bring some light to chase away the darkness? Enter the rap group that changed everything so completely that the record industry had to tear up its playbook and rethink the way it operated. A nine-strong, hydra-headed flurry of sparring egos, clashing styles, and ever-increasing self-belief; a band who wrote their own mythology, and came with an army of acolytes and a surplus of alter egos. They represented their rap band as superheroes, and today, who else but the Wu-Tang Clan could resuscitate a genre that some feel is breathing its last breath?

"This record has traveled all around the world," explains Robert "RZA" Diggs as he puts the finishing touches on the Clan's fifth album, 8 Diagrams, in a Toronto studio. "It started in L.A., moved to New York, came over to Europe with us on the road, hit a few countries there, and now it's finishing up in Canada. I leave it up to the critics to say whether you can hear all that in the record," he grins. "Maybe somebody'll say, 'RZA, next time you do your fuckin' album, stay in the basement!' Or maybe people will feel the movement and feel the places. We'll see what translates into the music."

Back when it all began in 1992, cousins RZA and GZA returned to their Staten Island home, licking their wounds after a couple of record deals had gone sour. Their choices were stark: give up the dream and go back to the business of day-to-day getting by, or use those experiences to come up with something new. There was no decision to make: RZA began work on his five-year master plan.

Recruiting from their army of friends and relatives, they assembled a rap supergroup: Clifford "Method Man" Smith, Russell "Ol' Dirty Bastard" Jones, Corey "Raekwon" Woods, Dennis "Ghostface Killah" Coles, Jason "Inspectah Deck" Hunter, Lamont "U-God" Hawkins and Elgin "Masta Killa" Turner. The nine emcees, each with a distinctive style and flow, went on to record first as a group, which announced each emcee as an individual artist in the music world. Their personalities established, each then released his own records, played his own shows, and carved his own niche in the pop culture edifice. Then, by their second group album, Wu-Tang had conquered the hip hop world.

Understanding both how rap audiences thought and how music was marketed, RZA knew they needed something other than skills and rhymes to succeed. He turned to the legends and sagas the group members grew up on - kung fu films, superhero comic books, and New York street lore - and created a mythological alternate reality the group would inhabit. The nine became the Wu-Tang Clan, named after a group of renegade monks with unparalleled skills in martial arts that made them so dangerous to society they had to swear never to teach their styles. The latter-day Wu-Tang Clan would battle not with nunchucks or Shaolin swords but with razor-sharp wit and densely packed lyrical metaphors. Their music sounded deliberately raw, a carefully considered contrast to the sleek production sheen hip hop had acquired that would remind rap fans of the grit and the roughness that had attracted them to hip hop in the first place.

RZA's plan worked almost to the letter. Five years after they released their debut single, the independently recorded, funded and distributed "Protect Ya Neck," the Wu-Tang Clan's second album, Wu-Tang Forever, crash-landed at No. 1 in both the U.S. and U.K. pop charts. The Wu revolution seemed complete.

Those first five years brought a slew of solo albums from the Clan, which saw their individual members grace the upper reaches of rap fans' all-time greatest lists. There were also two later group albums - The W and Iron Flag - the former giving the Clan their biggest U.K. hit single, "Gravel Pit." But by 2001, things had changed. "Suddenly, you're dealing with nine generals," RZA recalls, employing a fitting military metaphor, "and generals are hard to control. Plus, everyone had they own manager - trying to get everyone on the same page got harder."

"I'm a person that comes from a teaching of, we don't deal with leaders, but we deal with leadership," RZA says. "That means each man got to carry his own bucket, and somebody's gonna always be the one amongst you who leaves the footprints. Being the most knowledgeable, basically, whatever I said, everybody agreed with it; or, if they didn't agree, they still submitted to it. But around the time we were making Wu-Tang Forever, it went from dictatorship to democracy, basically. And when I went to that democracy, yo, that, to me, was the decline."

"What you heard on 36 Chambers was the hunger and the thirst," GZA analyzes. "Wu-Tang Forever was quenching that thirst - like, 'Aaah, that water and food tasted so good!' I would say The W was 'Let's eat again, I'm kinda hungry again.' But Iron Flag was probably like, 'Man, I don't wanna eat that right now, I'm kinda full.'" With the death of Ol' Dirty Bastard, who collapsed during a recording session late in 2004, it looked like the end for the group.

Cut to 2007. Freshly signed to Bodog Music in Europe, the eight remaining emcees have got a rumble in their collective belly once again. RZA is back in charge - "I'm in year three of my new five-year plan," he grins - and the Clan have at last been back in the studio. Where recording for The W and Iron Flag was a piecemeal affair, members dropping in when solo and external commitments permitted, for 8 Diagrams, RZA laid down the law once again. "When we started this, I tried to get them to think of it like a job," he explains. "To turn up at the same time every day and put in the work."

With ideas flowing, RZA was able to fashion a hip hop blockbuster using the techniques he'd been learning from his work in the movie business. "I actually produced this album like a movie director would do a movie," he says. "When you do a movie, first you write the script, then you do pre-production and scouting, then you film it, and then you edit it. With the album, the first month was to get lyrics, then the second month was focusing the lyrics and making them into songs. The third month was to make sense of it - I took it on the road, making changes, adding things. And now it's in the editing stage."

RZA worked with a number of outside producers on the record, though not all their tracks will make it onto the finished album. Easy Moe Be has definitely made the cut, but contributions from Q-Tip, Marley Marl and DJ Scratch are all either out or doubtful after problems with sample clearance. The collaboration with Chic's Nile Rogers isn't quite ready, and may be used for U-God's forthcoming solo album.

As well as the surviving eight Clansmen and regular acolytes Cappadonna and Mathematics, 8 Diagrams features considerable non-Clan input. The bands Stone Mecca and Sound Guild provide a mixture of improvised sounds to RZA's beat skeletons, playing music the Wu leader has written and scored for them. Other guests include System of a Down's bassist Shavo Odadjian ("Thug World"), and George Clinton ("Wolves"). Dhani Harrison, the son of the late Beatle, George, plays a guitar donated by none other than Russell Crowe (whom RZA worked with in the movie American Gangster) on "My Heart Gently Weeps," a track based on his father's "While My Guitar Gently Weeps." The song, which may be the album's first single, also features Erykah Badu and the Red Hot Chili Peppers' John Frusciante.

Their fallen friend Ol' Dirty Bastard is, as always, very much in the band's thoughts. "Life Changes" is a new track in which each surviving Clansman "came on and said some lyrics, sayin' goodbye to ODB and givin' some last-minute thoughts on him," as RZA explains. Dirty appears, too, on "Chamber Number Nine," an old track recently rediscovered in the Wu-Tang vaults, which RZA may not include on the U.S. release but says is a must for European versions of the album. "I'll be honest: I think the European audience will appreciate it regardless of what condition it's in," he explains. "America is more meticulous, and more to the bling, and if they get a song that don't got good quality on it, they're not gonna give it the chance. So if I can't fix it in the masterin', I'm still gonna put it on the album, but I'm gonna put it on the European version as a bonus. In America, when Wu-Tang come on stage we gotta have all our diamonds on, but out in Europe I can just have on my Wu-Tang shirt and I'm good. Our shows in the summer really brought that home to me. I appreciate comin' to a hip hop concert and it ain't all about how much money I got, it's about my talent. And that's the reason why I'll give that gift to 'em."

Track selection is narrowing, and RZA still has around 26 songs he would like to include, but feels that 16 would be the perfect number. He is still keeping his cards close to his chest, though, with even fellow band members unsure which songs will make it onto the record. "What I've heard so far, that vibe and energy is strong," says GZA, acknowledging that only The Abbott RZA can really predict what the record will sound like. "But it's authentic, strong hip hop, lyrically and musically."

Although titled after "one of the greatest kung fu films ever," in RZA's view, 8 Diagrams has a multiplicity of meanings, relating to the I Ching, chess, and numerology. "And also it goes right to the Wu-Tang," RZA adds, "to the eight remainin' members. We began almost as enemies, some of us, but we became friends and brothers under one banner, and we was able to spread that brotherhood throughout the world."