Pirates of the Caribbean: Captain Jack's last treasure

Through a small side-door, minding the spools of power cables and low-hanging beams, then down a flight of stone steps, can be found Singapore, circa 1720... the Pirates of the Caribbean version of Singapore, that is. Built on a studio sound-stage in sun-baked Los Angeles,, the place feels authentically humid. A stone quay leads to a labyrinth of rickety houses built on stilts, joined by a series of spindly bridges. At one end is a bathhouse which, intermittently explodes, emitting smoke, debris and a flood of strange individuals including Orlando Bloom, Keira Knightley and Geoffrey Rush.

Gore Verbinski laughs, stepping out from behind a bank of monitors. For a director contending with a £150m (according to industry sources) movie, it is admirable that he can still see the ironic side of things. "What madman would attempt that?" Then again, the 43-year-old, of Polish extraction but born and bred in Tennessee, has been shooting the two sequels to the hugely successful Pirates of the Caribbean: The Curse of the Black Pearl, often mixing the strands from day to day, over two and half years. Currently things are, to some extent, a bit easier (although no one will admit it). The second film, Pirates of the Caribbean: Dead Man's Chest, has passed through its run from cinema to DVD to become a £500m hit. In the meantime, the thousands of cast and crew have reunited for a further three months.

Thus we're in Singapore, where events will reconvene for the opening scene of At World's End, the third and final part in the trilogy. "These two films come 10 months apart, and that is the reality," continues Verbinski, ignoring the bustle of technicians re-rigging explosives. "Your enemy isn't politics or your clout with a studio. Your enemy as director is just having it ready by a certain date."

That this whole Pirates madness, a seemingly foolish gambit to turn a Disney theme-park ride into an old-fashioned swashbuckling romp, as piloted by mega-producer Jerry Bruckheimer and starring Johnny Depp, has become a phenomenon, just adds to the pressure ("expectation can kill you," admits Bruckheimer later).

For one thing, only a year after the sequel, how do you keep all this messing about in ships fresh for an audience which has got used to the Jack Sparrow joke?

"Well, it helps that you're finishing things," says Verbinski, aware that Dead Man's Chest suffered for staying in the water too long - it became bloated and wrinkly. "It would be a mistake to just try and glob on more gratuitous action, so there is a kind of purposeful step to the left here. We've got to get our characters going again... That is what is going to make it fresh. We are not just trying to outdo Dead Man's Chest, but turn it on its head."

Chief to Verbinski's thinking, and that of his writers Terry Rossio and Ted Elliott, as well as Depp, who has a large creative input, the third part needs to provide more folk for Jack to "rub up against". "If you just made the Johnny Depp movie, it's just too much of one flavour," explains the director, who has had as much to do with creating the quirky character as his leading man. "It's such a powerful performance that you need some kind of broth to put it into."

Thus Rush returns from the dead as the drawling no-gooder Barbossa who, alongside series regulars Bloom (the dashing Will Turner) and Knightley (the purposeful Elizabeth Swann), mount a rescue mission to free Jack from Davy Jones's Locker. The mission takes them first to Singapore. Here, within the confines of the bathhouse decorated with stretches of outlandish fungus (some of it growing on the patrons), we meet Sao Feng, the pirate lord of all Singapore and as big and flamboyant a rapscallion as Jack. He's played by Hong Kong superstar Chow Yun-Fat, who is currently to be found giving his director a hug.

"Welcome to Singapore," says Chow, giving a foul grin: his teeth are as black as Jack's are golden. "This is my movie now, Johnny is locked up far away. Time for me! I even got to take his trailer! I'm the pirate king."

Chow, who has indeed been borrowing Depp's trailer in his absence, has become the new star of the set. His manners are impeccable, and his good humour never slips. Describing his invitation to join the trilogy as a "real honour", he has revived a weary set with his boyish enthusiasm. "I just said, 'yes', straightaway. This is a new kind of adventure for me. But Feng, he's not to be trusted, he's a true pirate."

He certainly looks it. Chow's head has been shaved and imprinted with peculiar blue tattoos (symbols for his "brotherhood"), his face is crisscrossed with scars, one vividly crossing an eye, and his beard twists and turns as if it is making a bid for freedom. In short, he looks spectacular; as do his cohorts, a pack of leering hounds, bare-chested and elaborately tattooed, cheering their "boss" from a nearby catering table. "Pretty good, huh?" he says, taking in his ugly gang. "Enough to put you off your lunch."

For Verbinski and the cast, Chow's arrival has been a blessing. The director describes him as "one of the finest human beings he has ever met". Chow will happily lug stands for the crew, and he seems to know everyone by name. "God, he is a lovely man," says Knightley, all but consumed by the bundles of burgundy velvet of her dress. "I don't know whether it's working in Chinese cinema as opposed to American, or whether it is just how he works, but he expects complete silence on the set. On American films it is a much more technical process and the technicians have the forum. When he came on, he commanded silence."

Today's scene, however, will countenance no silence - the pyrotechnics have put paid to that. The heroes have gathered in Singapore to parlay with Feng, the sly dog who shares a dark back-story with Jack, and is in possession of the charts for Davy Jones' Locker. "Feng plays both of sides of the knife," says Verbinski. "He has a great heart but is also willing to betray everybody to get what he needs. Then pretty much every character is like that. They're pirates."

Let's recap. Johnny Depp, as that Rolling Stone of the high seas Jack Sparrow, is supposed to be dead, consumed by the Kraken sent by Davy Jones (Bill Nighy). Jones's heart (the means to control the ocean) is now in the clutches of Lord Beckett (Tom Hollander) who is out to eradicate piracy. The revived Captain Barbossa has the knowledge of how to get Captain Jack back. Meanwhile, Turner and Swann are running into romantic problems (again). And Disney expects another £500m bonanza from its biggest-ever franchise.

"I don't care about the money," grumbles Verbinski, averse to talking about the financial gains. "Not that it's not important to be successful, but you have to serve the story first." He would rather emphasise the third movie's mythological aims. It is, according to its creator, about the ending of an era, the pirate era. "Like for the gunfighter in a Western when the railroad comes to town."

As this Singapore venue promises, it is also now working on a global scale. The film's pirate hierarchy (all based on genuine brigands) must unite to oppose the offensive of the East India Company. "Yes, it is the big corporation trying to snuff out the independents," admits Bruckheimer, without irony. The slender, quietly spoken but eminently successful producer likes to drop onto set when journalists are visiting.

But for Verbinski, who in his skittish youth played guitar in punk bands, the films still represent subversion rather than homogenised product. Even if a trillion toys and computer games accompany the series, Verbinski will not give up his quest to play pirate among Hollywood's shipping lanes. "There is a wonderful mythology in these films," he coos. "And the death of myth in the name of progress is a really compelling idea. If the myth is dying, where does that put Jack Sparrow?"

He hopes to invest the final film with what he likes to call "those awkward moments" that enervated the first, those points where the plot slipped its formulaic rails for the entirely unexpected. "That was the gift of the original - the willingness to run absurdity against romanticism," he explains. "You are desperately trying to look for the original thought. Gravity pulls you into mediocrity so quickly."

Surely the presence of Captain Teague, played by the permanently half-mast Keith Richards, the man who might even be Captain Jack's dad, will make a suitably dissonant addition to the game? "I don't think I'll ever have another day on set that is quite like that," says Verbinksi of the three days they had Richards on set to complete his much-mooted cameo, the nature of which remains very much under wraps. "He's just such a unique species."

Yet there's no escaping that deadly weight of expectation. It is hardly punk-rock film-making when you're spending £150m ("I don't know if that figure is true; that's Disney's business - I just think it's important that the audience gets its money's worth," hedges Bruckheimer) on astounding audiences all over again. The new film even includes a sequence where a ship is carried across a desert on the back of a thousand crabs - that kind of thing doesn't come cheap.

And if the film was to bag another billion dollars for the East Disney Company, would Bruckheimer, Verbinski and Depp and the fleet of actors be forced to go through the whole thing again? "We are done," says Bruckheimer. "But there is a sliver of story..."

The cast is more circumspect about the idea. Depp announced with a flourish that he would make 30 of the things if they could manage a story (perhaps overstating things is as good as a denial). Knightley can only groan: "This is the end. Trilogies tend to come in threes. But who knows? I've not heard anything officially. I can't imagine doing another Pirates film."

Bloom, ducking out to the car park during lunch, suggests that it is about time that he put aside childish things and did some acting. "I've kind of used up this whole trilogy thing. It would be nice to do a film without a sword for once," he says, before concluding, if only to keep his agent happy: "If it were to take another form down the line... who knows?"

Back on the sweltering sound-stage, where technicians are now testing a series of catherine-wheels and rockets (a fireworks stall is about to go up in flames), Verbinski has no illusions that the studio will be cooking up yet more sequels. "We've concluded our tale," he growls. "From a corporate standpoint I am sure there are ideas. From my standpoint, I want to spend time with my family."

'Pirates of the Caribbean: At World's End' opens on 24 May