But I stride and stride, and I still feel no better. My head's aching and my eyes are red and I could really do with a drink or something. Just a little something, to make me feel a bit better. A drink, or a cigarette, or… I look up, and I'm in front of Octagon. My favourite shop in the whole world. Three floors of clothes, accessories, furnishings, gifts, coffee shops, juice bars and a florist which makes you want to fill your entire home with flowers.

I've got my purse with me.

Just something small, to cheer me up. A T-shirt or something. Or even some bubble bath. I need to buy myself something. I won't spend much. I'll just go in, and…

I'm already pushing my way through the doors. Oh God, the relief. The warmth, the light. This is where I belong. This my natural habitat.

Except that even as I'm heading towards the T-shirts, I'm not quite as happy as I should be. I look through the racks, trying to recreate the excitement I usually feel at buying myself a little treat – but somehow today I feel a bit empty. Still, I choose a cropped top with a silver star in the middle, and put it over my arm, telling myself I feel better already. Then I spot a rack of dressing gowns. I could do with a new dressing gown, as a matter of fact.

As I finger a lovely white waffle robe, I can hear a little voice at the back of my head, like a radio turned down low. Don't do it. You're in debt. Don't do it. You're in debt.

Yes, well, maybe I am.

But quite frankly, what does it matter now? It's too late to make any difference. I'm already in debt; I might as well be more in debt. Almost savagely, I pull the dressing gown down from the rack and put it over my arm. Then I reach for the matching waffle slippers. No point buying one without the other.

The checkout-point is directly to my left, but I ignore it. I'm not done yet. I head for the escalators and go up to the home-furnishing floor. Time for a new duvet set. White, to match my new dressing gown. And a pair of bolster cushions, and a fake-fur throw.

Every time I add something to my pile, I feel a little whoosh of pleasure, like a firework going off. And for a moment, everything's all right. But then, gradually, the light and sparkles disappear, and I'm left with cold dark blackness again. So I look feverishly around for something else. A huge scented candle. A set of Jo Malone shower gel and moisturizer. A bag of handmade potpourri. As I add each one, I feel a whoosh – and then blackness. But the whooshes are getting shorter and shorter each time. Why won't the pleasure stay? Why don't I feel happier?

'Can I help you?' says a voice, interrupting my thoughts. A young assistant, dressed in the Octagon outfit of white shirt and linen trousers, has come up and is looking at my pile of stuff on the floor. 'Would you like me to hold some of these while you continue shopping?'

'Oh,' I say blankly, and look down at the stuff I've accumulated. It's actually quite a lot by now. 'No, don't worry. I'll just… I'll just pay for this lot.'

Somehow, between us, we manage to lug all my shopping across the beechwood floor to the stylish granite checkout point in the middle, and the assistant begins to scan everything through. The bolster cushions have been reduced – which I hadn't realized – and while she's checking the exact price, a queue begins to form behind me.

'That'll be ?370.56,' she says at last, and smiles at me. 'How would you like to pay?'

'Erm… Switch card,' I say, and reach for my purse. As she's swiping it, I eye up my carrier bags and wonder how I'm going to get all this stuff home.

But immediately my thoughts bounce away. I don't want to think about home. I don't want to think about Suze, or Tarquin, or last night. Or any of it.

'I'm sorry,' says the girl apologetically, 'but there's something wrong with your card. It won't authorize the purchase.' She hands it back to me. 'Do you have anything else?'

'Oh,' I say, slightly flustered. 'Well… here's my VISA card.'

How embarrassing. And anyway, what's wrong with my card? It looks all right to me. I must complain to the bank about this.

The bank. Meeting tomorrow, with Derek Smeath.

Oh God. Don't think about it. Quick, think about something else. Look at the floor. Glance about the shop.

There's quite a big line of people behind me now, and I can hear coughing and clearing of throats. Everyone's waiting for me. As I meet the eye of the woman behind me, I smile awkwardly.

'No,' says the girl. 'This one's no good either.'

'What?' I whip round in shock. How can my VISA card be no good? It's my VISA card, for God's sake. Accepted all over the world. What's going on? It doesn't make any sense. It doesn't make any-

My thoughts stop mid-stream, and a nasty chill feeling begins to creep over me. All those letters. Those letters I've been putting in my dressing-table drawer. Surely they can't have…

No. Don't say they've cancelled my card. They can't have done.

My heart starts to thump in panic. I know I haven't been that great at paying my bills – but I need my VISA card. I need it. They can't just cancel it, just like that. Suddenly I feel rather shaky.

'There are other people waiting,' says the girl, gesturing to the queue. 'So if you aren't able to pay…'

'Of course I'm able to pay,' I say stiffly, aware that my cheeks are now flaming red. With trembling hands I scrabble in my purse and eventually produce my silver Octagon charge card. It was buried under all the others, so I can't have used it for a while. 'Here,' I say. 'I'll put it all on this.'

'Fine,' says the girl curtly, and swipes the card… It's only as we're waiting silently for the authorization that I begin to wonder whether I've actually paid off my Octagon account. They sent me a nasty letter a while ago, didn't they? Something about an outstanding balance. But I'm sure I paid it off, ages ago. Or at least, some of it. Didn't I? I'm sure I-

'I'm just going to have to make a quick call,' says the assistant, staring at her machine. She reaches for the phone next to the till, and dials a number.

'Hi,' she says. 'Yes, if I can give you an account number…'

Behind me, somebody sighs loudly. I can feel my face growing hotter and hotter. I don't dare look round.

I don't dare move.

'I see,' says the assistant eventually, and puts down the phone. She looks up – and at the sight of her face, my stomach gives a lurch. Her expression isn't apologetic, or polite any more. It's plain unfriendly.

'Our financial services department would like you to contact them urgently,' she says curtly. I’ll give you the number.'

'Right,' I say, trying to sound relaxed. As though this is a fairly normal request. 'OK. Well, I'll do that. Thanks.' I hold my hand out for my charge card. I'm not interested in my shopping any more. All I want to do is get out of here as quickly as possible.

'I'm sorry, I'm afraid your account's been frozen,' says the assistant without lowering her voice. 'I'm going to have to retain your card.'

I stare at her in disbelief, feeling my face prickling with shock. Behind me there's an interested rustle as everybody hears this and starts nudging each other.

'So, unless you have another means of paying…' she adds, looking at my heap of stuff on the counter. My waffle robe. My new duvet set. My scented candle. A huge, conspicuous pile of stuff. Stuff I don't need. Stuff which I can't pay for. Suddenly the sight of it all makes me feel sick.

Numbly I shake my head. I feel as if I've been caught stealing.

'Elsa,' calls the assistant. 'Will you deal with this, please? The customer isn't going to make the purchase after all.' She gestures to the pile of stuff, and the other assistant moves it along the counter, out of the way, her face deliberately blank.

'Next, please.'

The woman behind me steps forward, avoiding my eye in embarrassment, and slowly I turn away. I have never felt so humiliated in all my life. The whole floor seems to be looking at me – all the customers, all the sales assistants, all whispering and nudging. Did you see? Did you see what happened?

With wobbling legs I walk away, not looking right or left. This is a nightmare. I just have to get out, as quickly as possible. I have to get out of the shop and onto the street and go…

Go where? Home, I suppose.

But I can't go back and face Suze and hear her going on about how sweet Tarquin is. Or even worse, risk bumping into him. Oh God. The very thought makes me feel sick.

What am I going to do? Where am I going to go?

Shakily, I begin to walk along the pavement, looking away from the mocking window displays. What can I do? Where can I go? I feel empty; almost lightheaded with panic.

I pause at a corner, waiting for a traffic light to change and look blankly at a display of cashmere jumpers to my left. And suddenly, at the sight of a scarlet Pringle golfing jumper, I feel tears of relief springing to my eyes. There's one place I can go. One place I can always go.

Home to my mum and dad.

Sixteen

When I turn up at my parents' house that afternoon with no warning, saying I want to stay for a few days, I can't say they seem shocked, or even surprised. In fact, so unsurprised do they seem, that I begin to wonder if they've been expecting this eventuality all along, ever since I moved to London. Have they been waiting every week for me to arrive on the doorsteps with no luggage and red eyes? They're certainly behaving as calmly as a hospital casualty team operating an emergency procedure that was rehearsed only last week.