It is the toast of New York, Paris and Los Angeles. It was feted at the Oscars, the London Film Festival and the MTV Awards. It is adored by the press, fought over by admirers and close, very close, to some of the most beautiful women in the world, including Nicole Kidman, Scarlett Johansson and Rachel Weisz.
The £800 Galaxy dress (for, of course, it has a name, as all fashion cults should) is currently the best-known outfit on the planet. It already had a firm following among followers of fashion, having appeared in glossy magazines ranging from American Vogue to Heat. But last week it was splashed across the papers because its designer, Roland Mouret, suddenly, and inexplicably, left the company which owns his name.
The shops have sold out of Galaxy dresses although you can pick one up on eBay for £1,600 - double the original price and about the same as it costs to buy a used car ('Am asking double,' posts the seller, 'because this is gold-dust.')
Sixteen hundred pounds for an off-the-peg dress might seem steep - particularly in a world where chic women are queuing up at Primark for a pair of £10 jeans. But then, £1,000 bags are 10 a penny these days. The fashion world is booming at the extremes. It is, perhaps, odder still that in 2005 - a full 11 years after we all got so het up about Liz Hurley and her safety-pin dress - we can still get so animated about a few panels of fabric and a natty neckline.
It's not as though Mouret is the only designer to have returned to the hourglass figure this season. Others to have done so include Alexander McQueen, Oliver Theyskens at Rochas, even Ralph Lauren. Why is the Galaxy 'The One'? What curious alchemy turns a great design idea into a hysterical hot potato, one which encourages grown women to phone the designer, begging, in tears, to get hold of one?
The Galaxy is the latest in a clutch of fashion pieces to have become so desirable that they are known by name alone - think the Birkin handbag by Hermes or the Le Smoking women's tuxedo trouser suit by YSL.
The question of why these particular items reach iconic status goes to the very heart of what makes modern fashion tick. And the brutal answer is that what turns them into must-haves is the fact that you can't have one. Yes, you. You will probably never own a Galaxy frock. Even if you've got the cash.
Trend forecaster Tyler Brule coined the phrase 'Uber Premium' for these little slices of can't-have. As the website trendwatching.com puts it, 'Uber Premium is everything that is truly out of reach of the majority of consumers. Not just financially, but also by not being invited, or by being too late.'
By now, of course, you're gagging to get yourself a Galaxy. So I have rung around the stores on your behalf ...
'Do you have any Galaxy dresses?' I ask the pleasant woman at Harrods. 'Hah!' she says . 'No way! We sold out over a month ago. You could put your name down for next season's Titanium dress, though.' Oh, that sounds promising. 'We have a waiting list of 40 already. And we're only getting 20 in.'
Oh.
'And there are no more being made.'
Oh.
'But I think Harvey Nichols may have had 10 Galaxies in today.'
Ah, that sounds promising.
'But they've got a waiting list of 500.'
Undeterred, I ring Harvey Nicks. Do they have a size 12 Galaxy?
'Um, hang on a minute. We have had some in today ...'
Cue some encouraging off-stage fumbling, during which time I have projected myself into my new Galaxy dress, undulating along the red carpet, probably at the premiere of my latest well-received art-house movie and ...
'I'm sorry, madam. The last one was sold exactly one minute ago.'
The Galaxy has been called 'the must-have slimming dress of the stars'. Cameron Diaz was an early adopter; Victoria Beckham slid into one for the Pride of Britain charity awards earlier this month. You might well have glimpsed a Galaxy on Rosamund Pike, or on Keira Knightley, unexpectedly turning her boyish frame into something wickedly saucy. Erin O'Connor wore a rule-breaking black one to Jodie Kidd's wedding. Demi Moore was among the first to step out in one. But this mega-dress really belongs to vixen model Carmen Kass. She wore the original felt version on the catwalk a mere eight months ago, and managed somehow to look like a cat on heat. Editors from Manhattan to Melbourne climbed over each other to get at the samples and shoot it first for their magazines.
No surprises, then, that actress Rachel Weisz chose it to wear to the premiere of her movie The Constant Gardener last week. Hers, though, was subtly different. Marginally longer, a different colour (the originals only come in tweed, chocolate and blue), with a kick pleat and a clever cutaway at the sleeve. The Galaxy had evolved. And the next generation - which Mouret has dubbed the 'Titanium' - is just as much a must-have as the last and even more expensive at £975.
I phone a fashionable friend to unravel its allure. 'It's a proper premiere dress, isn't it?' she says. 'I mean, even if you're not ever going to go to a premiere, it pushes all the right glamour buttons. It's that unusual thing: a dress which is both sexy and chic. Very rare combination.'
She's right. Over the past few years, 'sexy' dressing has come to mean baring as much flesh as is humanly possible without being arrested for streaking. Witness Victoria Beckham in her Cavalli get-up last week. But true sex appeal - as most women in the Fifties knew, and as we are beginning to remember - is as much about what you cover up as what you put on display. The Galaxy, which is, in fact, rather reserved and classy, chimes with the new taste for all things womanly. It smoulders. It recalls Marilyn in Some Like it Hot, Jayne Mansfield in The Girl Can't Help It, Tippi Hedren in Birds
To get all that va-va-voom into one rather modest dress, the designer mounted it on Powermesh, a French fabric from the Fifties used to reinforce underwear. 'It is an integral part of the dress, rather than an undergarment,' explains my man at Mouret. 'Once you're zipped in, your body moves with it. It means that whether you are a size 6 or 14 you will look fantastic in it...'
Doubtless, it helps that the designer himself is something of a pull. Mouret is, according to industry insiders, 'colourful, handsome, charismatic ... master of the sharply controversial sound bite'. He's a charmer. And, as one perspicacious pundit put it recently: 'Women don't just want to buy clothes, they want to buy into a lifestyle and a provenance.'
Mouret was born in Lourdes, to a butcher father and waitress mother, 44 years ago. 'It was like growing up in a funfair,' he says. 'All the lights in the shops. It was like a religious Dallas.' He worked as a model for Jean Paul Gaultier, a stylist for French Glamour and an art director for Robert Clergerie. In 1994, having moved to London, he opened the fashionable Soho bar Freedom. 'I met Lee [Alexander] McQueen there,' he says, 'and Katy [England] and Hussein [Chalayan].'
By 1998, he was in a London Bridge kitchen designing his first own-name collection - an engaging fusion of drapery, glamour and beauty which caused a quiet storm among the more measured members of the fashion press.
In 2000, he met Sharai Meyers and her millionaire husband Andre, who became his financial backers, allowing him to step up his operation and show his collections alongside some of the world's major players in New York. 'It was like love at first sight when we met,' said Mouret of Meyers at the time. 'We just clicked.' Five years into the relationship, and the click created a cult - that gorgeous Galaxy.
Which makes it all the more puzzling that Mouret has chosen this past week to quit his company. It is a move which has astonished the fashion press - not least because the Meyers own 100 per cent of the company's equity. Mouret has, therefore, lost the rights to his name - the one suddenly on everybody's lips - along with vast potential earnings. Many believe that it is the worst possible time for the departure: sales at the house have hit £2.8million this season; Mouret has been nominated as Designer of the Year at next month's British Fashion Awards.
'Like all relationships, you can either grow together or go down different paths,' says Sharai Meyers. 'It really was no one thing, simply a realisation that we didn't share the same vision any more ... It is a great shame.' The company insists that orders will be met, the label will go on.
Meanwhile, the Galaxy is following the usual trajectory of a must-have look: from A-list to B-list to the general public. Last week, Carol Vorderman wore one to Des Lynam's book launch and Jennifer Ellison was snapped in a Galaxy outside the Theatre Royal. And, should you find yourself in TopShop, you can now pick up a Galaxalike - black stretch satin and a steal at £40.
OK, so it's a ropey knockoff, and what you desperately want is the Real Thing. But, given that its designer has left the building, the Galaxy is now rarer still. It is Super Uber Premium. I suggest that our friend on eBay doubles her asking price before someone snaps up the bargain.