“A day?” My heart starts to thump in panic. “Just one day?”

“One day,” affirms the girl solemnly. I glance at the other girls — and they’re nodding in agreement.

“Sample sales come without much warning,” explains one.

“They can be anywhere. They just appear overnight.”

“Then they’re gone. Vanished.”

“And you just have to wait for the next one.”

I look from face to face, utterly mesmerized. I feel like an explorer learning about some mysterious nomadic tribe.

“So you wanna catch this one today,” says the girl in blue, tapping the card and bringing me back to life, “you’d better hurry.”

I have never moved as fast as I do out of that shop. Clutching my Saks Fifth Avenue carrier, I hail a taxi, breathlessly read out the address on the card, and sink back into my seat.

I have no idea where we’re heading or what famous landmarks we’re passing — but I don’t care. As long as there are designer clothes on sale, then that’s all I need to know.

We come to a stop, and I pay the driver, making sure I tip him about 50 percent so he doesn’t think I’m some stingy English tourist — and, heart thumping, I get out. And I have to admit, on first impression, things are not promising. I’m in a street full of rather uninspiring-looking shop fronts and office blocks. On the card it said the sample sale was at 405, but when I follow the numbers along the road, 405 turns out to be just another office building. Am I in the wrong place altogether? I walk along the pavement for a little bit, peering up at the buildings — but there are no clues. I don’t even know which district I’m in.

Suddenly I feel deflated and rather stupid. I was supposed to be going on a nice organized walking tour today — and what have I done instead? I’ve gone rushing off to some strange part of the city, where I’ll probably get mugged any minute. In fact, the whole thing was probably a scam, I think morosely. I mean, honestly. Designer clothes at 70 percent discount? I should have realized it was far too good to be—

Hang on. Just… hang on a minute.

Another taxi is pulling up, and a girl in a Miu Miu dress is getting out. She consults a piece of paper, walks briskly along the pavement, and disappears inside the door of 405. A moment later, two more girls appear along the street — and as I watch, they go inside, too.

Maybe this is the right place.

I push open the glass doors, walk into a shabby foyer, and nod nervously at the concierge sitting at the desk.

“Erm… excuse me,” I say politely. “I was looking for the—”

“Twelfth floor,” he says in a bored voice. “Elevators are in the rear.”

I hurry toward the back of the foyer, summon one of the rather elderly lifts, and press twelve. Slowly and creakily the lift rises — and I begin to hear a kind of faint hubbub, rising in volume as I get nearer. The lift suddenly pings and the doors open and… Oh my God. Is this the queue?

A line of girls is snaking back from a door at the end of the corridor. Girls in cashmere coats, girls in black suits, girls tossing their springy ponytails around, and chattering excitedly into their mobile phones. There’s not a single one who isn’t wearing full makeup and smart shoes and carrying some sort of designer bag, even if it’s the teeniest little Louis Vuitton coin purse — and the babble of conversation is peppered with names of fashion houses. They’re all pressing forward, firmly moving their stilettos inch by inch along the floor, and all have the same urgent look in their eyes. Every so often somebody pushes their way out of the door, holding an enormous, nameless carrier bag — and about three girls push their way in. Then, just as I join the end of the line, there’s a rattling sound, and a woman opens up a door, a few yards behind me.

“Another entrance this way,” she calls. “Come this way!”

In front of me, a whole line of heads whips round. There’s a collective intake of breath — and then it’s like a tidal wave of girls, all heading toward me. I find myself running toward the door, just to avoid being knocked down — and suddenly I’m in the middle of the room, slightly shaken, as everybody else peels off and heads for the racks.

I look around, trying to get my bearings. There are racks and racks of clothes, tables covered in bags and shoes and scarves. I can already spot Ralph Lauren knitwear… a rack full of fabulous coats… there’s a stack of Prada bags… I mean, this is like a dream come true! Everywhere I look, girls are feverishly sorting through garments, looking for labels, trying out bags. Their manicured nails are descending on the stuff like the claws of birds of prey and I can’t believe quite how fast they’re working. As I see the girl who was standing in front of me in the line, I feel a surge of panic. She’s got a whole armful of stuff, and I haven’t even started. If I don’t get in there, everything will be gone. I have to grab something now!