Of Copenhagen, as it went past his window, Roper saw a million lights reflected in black water, a gallery of mirrors by night. There was a twisted gold spire and a curious black tower reaching into the sky like a tree root. He saw yellow buses, women pushing prams as big as barges and crowds of people slowly cycling along the pavement.

A taxi had been sent to collect him from Kastrup Airport. It was lined with carpet and felt like a warm sock. The driver drummed his fingers on the steering wheel and said nothing.

Roper was dropped outside an old building fronting the docks. It had a large wooden entranceway with a door set into it, and this door was ajar. On the other side there was a dank passage leading to an inner courtyard, its cobbles shiny with melted snow.

There were many doors, but Roper followed the instructions the old Danish lady had given him and continued straight ahead, across the courtyard, to the door furthest away. Before entering, he craned his neck to see the sky framed in a dull orange square high above him. There was the distant rumble of an aeroplane.

The lights went out on the second floor of the stairwell, and Roper was fumbling on the wall for the switch when the sound of a door being opened somewhere above him made his armpits prickle coldly.

‘Come on,’ he mumbled, clutching the leather satchel containing the pittance in Danish kroner that he had agreed to pay for the Chinese vase. ‘You’re not afraid of a little old lady now, are you?’

He felt quite sure that the vase was genuine Qing dynasty. Mrs Vinterberg had described all the markings and colours to him in great detail. Though, of course, as far as she knew it was worthless. ‘A common reproduction artefact. We see a lot of them in London,’ he had told her.

To Roper’s mind, lying in this way was not unfair. As far as he was concerned, it was caveat venditor: vendor beware. Besides, ridding the elderly of their unwanted clutter was nothing less than an act of charity.

Finding the light switch, he continued upwards with renewed determination, until he reached the open door.

‘Mrs Vinterberg?’ he called softly on entering.

The hall had a chequerboard floor and wall lamps set into wood panelling. Roper felt as though he had stepped on board a ship, one of the old-fashioned classy liners.

‘Hello? Anyone here?’ he said, only to jump at the door shutting with a heavy clunk. Then came the peculiar guttural accent he remembered from the telephone.

‘Mr Roper, how do you do.’

Mrs Vinterberg – a tiny, breakable thing of at least eighty – had been in the hall all along, hovering behind the door. She was dressed eccentrically in a long sequinned caftan with a turban made from colourful silks, and had mournful eyes and waxy skin.

Roper towered over her as she spoke.

‘You will join me for a cup of tea, yes?’

Without waiting for a reply, she led him through to a cavernous lounge. Roper had to stop in the doorway and steady himself. On every vertical surface there were framed paintings and sketches and photographs. Oriental rugs covered the floor and there were several sofas, tables and gilded lamps. He wondered how many objects he could fit in his suitcase besides the Chinese vase.

Mrs Vinterberg had set a small table for tea and rattled the cups in their saucers as she poured. Roper took a big mouthful but almost spat it out again.

‘What’s this?’ he said, frowning as the hot liquid slid down his throat. It had an aftertaste that was at the same time sweet and unpleasant, like bitter almonds.

‘Black China tea,’ Mrs Vinterberg said, smiling mischievously. ‘With a dash of rum.’

‘Thank you. It’s … awfully nice of you, Mrs Vinterberg, the tea and everything.’

Roper forced a smile of the sort that usually worked on old ladies. ‘Now, where would you be keeping that pretty vase of yours?’ he ventured.

‘Oh,’ said Mrs Vinterberg, a look of regret passing over her melancholic features. ‘You are in a hurry.’

‘No, no,’ Roper lied. ‘Please forgive my impatience. I didn’t mean to rush you.’

‘That’s quite all right, Mr Roper,’ she replied. ‘You want to get on, I understand.’

‘All in good time,’ he said, sipping his tea. ‘I’m never too busy for a chat. Quite a place you have here, Mrs Vinterberg. Did you collect all these antiques yourself?’

Having spoken, Roper felt tired all of a sudden and suppressed a yawn that brought tears to his eyes, but Mrs Vinterberg didn’t seem to notice. It was as though her gaze had turned inwards.

‘My father bought most of them,’ she said. ‘He owned ships, freightliners, but they took a few passengers too. All over we went. New York, Sydney, Panama, Casablanca, Marseilles. It was a different world then. People took their time over things. I remember a long journey in the summer of 1952, bringing us from Copenhagen to Hamina in Finland and passing by Rouen, Bristol and Newcastle. England has always been special to us Danes, because of what you people did in the war.’

Roper couldn’t see what any of this had to do with him, nor why Mrs Vinterberg would want to be telling all this to a complete stranger who had merely answered her advertisement in the Sunday Times.

She suddenly cackled loudly to herself. ‘You know, I love that thing you do in London theatres where drinks are left out in the interval and you can take anything you want.’

‘You’re supposed to have paid for them,’ Roper mumbled into his teacup.

Having listened to the old lady for several more minutes, he began to look irritably at his watch. He had spent a good half hour with Mrs Vinterberg, but she hadn’t as much as mentioned the vase. And now there was this strange tiredness, filling his eyelids with sand.

‘Look,’ he said, cutting off another of her rambling anecdotes. ‘I don’t mean to be rude, but I’ve had rather a long day. Do you think you could possibly fetch that vase now? I have the money right here, and then we can both get on with our business.’ He patted the leather satchel.

Mrs Vinterberg sighed and put down her cup. ‘Of course.’

‘Not that I’m not enjoying our chat or anything.’

‘No, no, you’re right,’ she said, but Roper could tell by the way her shoulders sloped that he had made a mistake.

‘It’s just that I don’t get many visitors here any more,’ she said ‘and I don’t care for being alone.’

‘I’m sorry to hear that,’ Roper said.

‘Everyone I ever knew, who knew me, is dead.’ The old lady’s eyes were fringed with black-tinted tears. ‘Is it so bad,’ she asked ‘to want a little company?’

‘No, of course not,’ Roper replied.

He was coming around to the view that humouring Mrs Vinterberg was the shortest route to the Chinese vase. But all of a sudden the old lady’s voice changed. She leant forward and placed a cold hand on his arm.

‘Stay, Mr Roper, please. Only for the night.’

Roper yanked his arm away in surprise. ‘No …’

‘Then just until I’ve gone to sleep, please … and I’ll let you go,’ she urged.

‘No,’ Roper said, getting up clumsily and knocking over his cup. He felt a spike of ice in his belly. What was happening to his legs?

‘Mr Roper, please,’ Mrs Vinterberg said desperately. ‘Sit down and have some more tea.’

‘No,’ he shouted, making her flinch. ‘You put something in it, didn’t you?’

She looked up at him, too calmly, he thought. ‘What do you mean? Mr Roper, are you all right?’

‘You did, you did,’ he said grabbing her by the front of her dress. ‘You spiked my tea.’

‘You are tired. Long journeys always make one dreadfully tired,’ she said, waving her hands about.

She was like a bird. He looked at her diminutive wrists, marbled with veins, her imploring eyes, and he knew at once that she was right. The flight had taken it out of him, and he had slept no more than two or three hours the night before.

He sat back down again and rubbed his eyes, tried to pull himself together.

‘I’m sorry,’ he said. ‘I don’t know what got into me.’

‘The tea will refresh you. Here,’ she said, pouring. Guiltily, he put the cup to his lips.

‘Look, Mrs Vinterberg, we seem to have got off to a bad start,’ he said before drinking another mouthful as she watched.

Afterwards, when he blinked, it seemed several minutes passed while his eyes were closed. He shook his head, but the room took its time to follow. It was as though the floor had started to move, gently swelling like the sea.

‘It is I who should apologise,’ Mrs Vinterberg said. ‘I expect you want to see the vase now?’

‘Yes, please,’ Roper said, but his voice seemed to come from somewhere outside himself.

‘It’s the most beautiful vase you ever saw. An old man, a refugee, gave it to me in Hong Kong in 1955,’ she said, but she was in no hurry to leave her chair.

Nattering on, she refilled Roper’s cup, but this time he pushed it away. A heaviness had settled on his brain and it took an age before he succeeded in commanding his lips to move.

‘Get it now,’ he said, his voice low and slurred. ‘Just get the vase.’

‘Say you will stay and I will give it to you. You can have it in the morning,’ said Mrs Vinterberg, who was far away now, as though he were looking at her down the wrong end of a pair of binoculars.

‘Crazy old bat,’ Roper said, managing with the last of his strength to pull himself up. He tried to seize her by the neck but she easily recoiled from his grasp, causing him to lose his balance. Something crashed to the floor.

‘For the last time,’ he gasped, bent over the arm of a chair. ‘Give me the vase. Right now.’

‘No.’

‘Bloody witch. I’ve had enough of this,’ he said and began to stagger across the oriental rugs, stuffing his pockets with Mrs Vinterberg’s candlesticks and silver trinkets.

He could still make it down to the street. He would flag down a taxi, catch a late plane back to London.

But the door he went through did not lead back to the entrance hall. Instead, Roper found himself in a smaller room so full of objects that it was a while before he comprehended what he was looking at: suitcases, at least a dozen of them, stacked on top of one another; neckties divided into colour sections and pinned to a wall; toothbrushes, wristwatches and colognes neatly laid out in rows and fans; boarding cards, wallets, passports, some of them ancient-looking.

‘My God, she is mad,’ he whispered.

Weighed down by the loot in his pockets, he fell to his knees, then onto his back, as he recalled the words of Mrs Vinterberg’s advertisement: Pretty Qing vase. Copenhagen. Must be collected in person.

Lying prostrate on a Persian rug, he noticed that the floorboards beneath him felt springy and loose. Was that where she kept them, the others who had come to buy her vase?

‘They wouldn’t stay,’ said the tiny Mrs Vinterberg, who had come up behind him on her silent feet. ‘No one ever will.’

Roper could no longer speak, not even scream. A plaintive ship’s horn sounded in the far distance, as Mrs Vinterberg leant over him, her features set in a rueful frown. ‘Goodbye, Mr Roper,’ she said.

Between her small hands, she held a white cushion with the words Baltic Marine Conference 1957 embroidered in navy blue. Roper, who by now could move only his eyes, turned his gaze to the window as she slowly extended the cushion towards his face.

He fancied he could see the velvet water of Copenhagen harbour with the million lights reflected in it, but it could have been the sky, shimmering with stars.

He closed his eyes and in a dream – his last – he saw Mrs Vinterberg come towards him on the wooden deck of a ship, a Chinese vase held aloft in her outstretched hands. The porcelain was the blue-tinged pearly white of a child’s first tooth, the motifs and markings just as she had described them. It was indeed a vase of extraordinary beauty, and he reached for it, almost touching it, as dozens of Danish banknotes slipped from his hand and flew up on the wind, blackening the sky.