It is A hot afternoon. The square is packed with visitors. Few spare a glance for the white-haired woman who, suitcase in hand, descends from the bus. She wears a blue cotton frock; her neck, in the sun, is burned red and beaded with sweat.

Past the pavement tables, past the young folk, the wheels of the suitcase rattling over the cobbles, she makes her way to the gate where a uniformed man stands drowsily on guard, propped on the rifle he holds butt down before him.

'Is this the gate?' she asks.

Beneath the peaked cap he blinks once in confirmation.

'Can I pass through?'

With a movement of the eyes he indicates the lodge to one side.

The lodge, put together of prefabricated wooden panels, is stiflingly hot. Inside, behind a small trestle table, sits a man in shirtsleeves, writing. A tiny electric fan blows a stream of air into his face.

'Excuse me,' she says. He pays her no attention. 'Excuse me. Can someone open the gate for me?'

He is filling in some kind of form. Without ceasing to write, he speaks. 'First you must make a statement.'

'Make a statement? To whom? To you?'

With his left hand he pushes a sheet of paper across to her. She lets go of the suitcase and picks up the paper. It is blank.

'Before I can pass through I must make a statement,' she repeats. 'A statement of what?'

'Belief. What you believe.'

'Belief. Is that all? Not a statement of faith? What if I do not believe? What if I am not a believer?'

The man shrugs. For the first time he looks directly at her. 'We all believe. We are not cattle. For each of us there is something we believe. Write it down, what you believe. Put it in the statement.'

There is no more doubt in her mind about where she is, who she is. She is a petitioner before the gate. The journey that brought her here, to this country, to this town, that seemed to reach its end when the bus halted and its door opened on to the crowded square, was not the end of it all. Now commences a trial of a different kind. Some act is required of her, some prescribed yet undefined affirmation, before she will be found good and can pass through. But is this the one who will judge her, this ruddy, heavy-set man on whose rather sketchy uniform (military? civil guard?) she can detect no mark of rank but on whom the fan, swinging neither left nor right, pours a coolness that she wishes were being poured on her?

'I am a writer,' she says. 'You have probably not heard of me here, but I write, or have written, under the name Elizabeth Costello. It is not my profession to believe, just to write. Not my business. I do imitations, as Aristotle would have said.'

She pauses, then brings out the next sentence, the sentence that will determine whether this is her judge, the right one to judge her, or, on the contrary, merely the first in a long line leading to who knows what featureless functionary in what chancellery in what castle. 'I can do an imitation of belief, if you like. Will that be enough for your purposes?'

His response has an air of impatience about it, as though this is an offer he has had many times before. 'Write the statement as required,' he says. 'Bring it back when it is completed.'

'Very well, I will do so. Is there a time when you go off duty?'

'I am always here,' he replies. From which she understands that this town where she finds herself, where the guardian of the gate never sleeps and the people in the cafés seem to have nowhere to go, no obligation other than to fill the air with their chatter, is no more real than she: no more but perhaps no less.

Seated at one of the pavement tables she briskly composes what is to be her statement. I am a writer, a trader in fictions, it says. I maintain beliefs only provisionally: fixed beliefs would stand in my way. I change beliefs as I change my habitation or my clothes, according to my needs. On these grounds – professional, vocational – I request exemption from a rule of which I now hear for the first time, namely that every petitioner at the gate should hold to one or more beliefs.

She takes her statement back to the guardhouse. As she half expected, it is rejected. The man at the desk does not refer it to a higher authority, apparently it does not deserve that, merely shakes his head and lets the page fall to the floor and pushes a fresh sheet of paper towards her. 'What you believe,' he says.

She returns to her chair on the pavement. Am I going to become an institution, she wonders: the old woman who says she is a writer exempt from the law? The woman who, with her black suitcase always beside her (containing what? – she can no longer remember), writes pleas, one after the other, that she puts before the man in the guardhouse and that the man in the guardhouse pushes aside as not good enough, not what is required before one can pass on?

'Can I just glance through?' she says on her second attempt. 'Take a glance at what lies on the other side? Just to see if it is worth all this trouble.'

Ponderously the man rises from his desk. He is not as old as she, but he is not young either. He is wearing riding boots; his blue serge trousers have a red stripe up the sides. How hot he must be, she thinks! And in winter, how cold! Not a cushy job, being guardian of the gate.

Past the soldier leaning on his rifle he takes her, till they stand before the gate itself, massive enough to hold back an army. From a pouch at his belt he takes a key nearly as long as his forearm. Will this be the point where he tells her the gate is meant for her and her alone, and moreover that she is destined never to pass through? Should she remind him, let him know she knows the score?

The key turns twice in the lock. 'There, satisfy yourself,' says the man.

She puts her eye to the crack. A millimetre, two millimetres he draws open the door, then closes it again.

'You have seen,' he says. 'The record will show that.'

What has she seen? Despite her unbelief, she had expected that what lay beyond this door fashioned of teak and brass but also no doubt of the tissue of allegory would be unimaginable: a light so blinding that earthly senses would be stunned by it. But the light is not unimaginable at all. It is merely brilliant, more brilliant perhaps than the varieties of light she has known hitherto, but not of another order, not more brilliant than, say, a magnesium flash sustained endlessly.

The man pats her on the arm. It is a surprising gesture, coming from him, surprisingly personal. Like one of those torturers, she reflects, who claim to wish you no harm, merely to be doing their sad duty. 'Now you have seen,' he says. 'Now you will try harder.'

At the café she orders a drink in Italian – the right language, she says to herself, for such an opera-buffa town – and pays for it with notes she finds in her purse, notes she has no recollection of acquiring. In fact, they look suspiciously like play money: on the one side the image of a bearded nineteenth-century worthy, on the other the denomination, 5, 10, 25, 100, in shades of green and cerise. Five what? Ten what? Yet the waiter accepts the notes: they must in some sense be good.

Whatever the money is, she does not have much of it: four hundred units. A drink costs five, with tip. What happens when one runs out of money? Is there a public administration on whose charity one can throw oneself?

She raises the question with the guardian of the gate. 'If you keep rejecting my statements I'll have to take up residence with you in your lodge,' she says. 'I can't afford hotel rates.'

It is a joke, she just means to shake up this rather dour fellow.

'For long-term petitioners,' he replies,'there is a dormitory. With kitchen and ablution facilities. All needs have been foreseen.'

'Kitchen or soup kitchen?' she asks. He does not react. Evidently they are not used to being joked with in this place.

The dormitory is a windowless room, long and low. A single bare bulb lights the passageway. On either side are bunks in two tiers, knocked together out of tired-looking wood and painted in the dark rust colour she associates with rolling stock. In fact, looking more closely, she can see stencilled characters: 100377/3 CJG, 282220/0 CXX… Most of the bunks have palliasses on them: straw in ticking sacks that in the close heat give off an odour of grease and old sweat.

She could be in any of the gulags, she thinks. She could be in any of the camps of the Third Reich. The whole thing put together from clichés, with not a speck of originality.

'What is this place?' she asks the woman who has let her in.

She need not have asked. Before it comes, she knows what the answer will be. 'It is where you wait.'

The woman – she hesitates to call her the Kapo just yet – is a cliché herself: a heavy-set peasant wearing a shapeless grey smock, a kerchief, sandals with blue woollen socks. Yet her gaze is even, intelligent. She has a teasing feeling she has seen the woman before, or her double, or a photograph of her.

'May I choose my own bunk?' she says. 'Or has that too been predetermined on my behalf?'

'Choose,' says the woman. Her face is inscrutable.

With a sigh she chooses, lifts the suitcase, unzips it.

Even in this town time passes. The day arrives, her day. She finds herself before a high bench, in an empty room. On the bench are nine microphones in a row. On the wall behind it, an emblem in plaster relief: two shields, two crossed spears, and what looks like an emu but is probably meant to be a nobler bird, bearing a laurel wreath in its beak.

A man she thinks of as a bailiff brings her a chair and indicates she may sit. She sits down, waits. The windows are all closed, the room is stuffy. She gestures to the bailiff, makes a motion of drinking. He pretends not to notice.

A door opens, and in file the judges, her judges, judges of her. Under the black robes she half expects them to be creatures out of Grandville: crocodile, ass, raven, deathwatch beetle. But no, they are of her kind, her phylum. Even their faces are human. Male, all of them; male and elderly.

She does not need the bailiff's prompting (he has come up behind her now) to stand. A performance will be required of her; she hopes she can pick up the cues.

The judge in the middle gives her a little nod; she nods back.

'You are…?' he says.

'Elizabeth Costello.'

'Yes. The applicant.'

'Or the supplicant, if that improves my chances.'

'And this is your first hearing?'

'Yes.'

'And you want -?'

'I want to pass the gate. To pass through. To get on with what comes next.'

'Yes. As you must have learned by now, there is the question of belief. You have a statement to make to us?'