The morning after the doctor told her she was dying, Gudrun Holm woke early, overwhelmed by despair for the chanterelles. The thought of them growing unnoticed in the forest after her death was unbearable.

She pushed back the covers and sat up in bed, wincing at the pain. It was everywhere now, not just in her chest. Her breaths were wheezy and ineffective, her lungs like perforated bellows.

Through the open window, she could hear the eternal sigh of the North Sea. The dawn air was damp and fragrant with rose hip and wet grass. No wind stirred the net curtains.

She snatched a whining mosquito out of the air and squashed its quivering limbs between her fingers before setting two feet on the cold floor.

Five generations of Holms had picked chanterelles in the great sand-dune plantations. She was the last of the line, the only person living to know where the chanterelles of Østvig grew.

Unless she told someone.

A stench of spoiled fish greeted her in the kitchen, last night’s cod. In the end, she had not had the appetite for it. She emptied the pan outside by the woodpile. Something would eat the fish – foxes, rats, gulls.

Like her body when they finally put her in the ground, the cod would be reclaimed by nature. Nothing was wasted in the end. Even her own flesh would make a feast, if only for maggots.

She looked out over the dunes, followed a V-formation of migrating geese pulling across the flat expanse of lyme grass and heather. The sky was bigger here than elsewhere in Denmark. The deep blue light cast a primeval glow on the landscape, as though it had never been morning there before. She licked her lips and tasted salt.

The vicar picked up on the seventh ring, his voice thick with sleep. ‘Gudrun. You are up early.’

‘Vicar, I’m dying,’ she said, brushing off his noises of sympathy. ‘But that’s not why I’m calling.’

‘No?’

She pictured the vicar squinting beneath his great domed forehead, his hand crabbing across the bedside table as he searched for his glasses. She stemmed her impatience at his dithering. After all, he had known her as a child and would, by long-standing agreement, be the one laying her to rest in a few short weeks. There would be no mourners.

‘I wish to pass something on to you,’ she said. ‘It’s about the chanterelles. I want to tell you where to find them.’ She allowed a pause for the vicar’s reaction. It wasn’t much.

‘Oh,’ he said. ‘Oh, I see.’

‘Well?’ she said. ‘Will you come with me today, so I can show you?’

When the vicar cleared his throat, she could tell that he was about to disappoint her.

‘I’m old, Gudrun, and won’t be long after you in Heaven. You don’t want to trust me with something so important,’ he said.

‘But you’re the only person I know,’ she protested.

The vicar did not bother to contradict her. Everyone knew that Gudrun Holm disliked people.

There was a moment’s pause before he spoke again. ‘Then there is only one other option.’

‘What?’ Gudrun asked suspiciously.

‘It’s obvious,’ he said. ‘It has to be someone you are yet to meet.’

She rang off.

‘Easy for you,’ she spat, her voice echoing in the empty house. ‘You forget this isn’t exactly Copenhagen Central Station.’

She sharpened her mushroom knife standing by the sink, soothed by the feel of its pear-shaped wooden handle in the palm of her hand. The kitchen window was greasy with sea fret. No matter how often she washed her windows, the sea always won.

After drying it carefully, she wrapped the knife in a dishcloth and placed it in the faded wicker basket that was older than herself. Then she slipped a worn tracksuit top over her T-shirt, found her battered leather walking boots and tied a multi-coloured scarf over the itchy stubble on her scalp.

The bones in her buttocks grated against the saddle as she cycled slowly up the dirt track. How many more days would she be able to do this before the rest of her strength ebbed away? Two? Three?

When she reached the main road, she looked to the left where the village houses lay like a jumble of Lego bricks on the horizon.

A car passed, a sleek black number with German plates. Østvig was not what it used to be, not since they had knocked up all those new holiday homes. Once there had been fourteen sky-blue boats fishing the North Sea from the village, a grocery shop, even a school. Now all the fishermen had cleared off, and Østvig had become a hollowed-out shell, overrun with tourists from May to October.

Someone had placed a sandwich board close to her drive. Straight on for ice cream. She got off her bike and kicked the sign into a rose bush, then had to hobble for a minute, holding her sore foot.

The road was empty but for a small local boy who stopped and stared at her, mouth agape, fish eyes frowning.

‘What are you looking at?’ she scowled, shaking her fist.

When the boy had gone, she turned right onto the main road and, after about five minutes, headed down the gravel track that cut like a ruler through the pine plantation.

The sound of the ocean was more muted here, like a distant exhalation. A wood pigeon called nearby. The air was sweet and mild and buzzing with insects.

Gudrun allowed herself a moment of self-pity that this place should be lost to her, and so soon.

Sweeping flies away from her face, she rested her bike against a silver birch and concealed it with bracken.

For as long as she could remember, she had been the guardian of the chanterelles, and what was to become of them without her? Who now would bear witness to their beauty?

Her father had shown her the almost invisible deer paths that criss-crossed these woods, pointing to the mould-coloured lichen, oak saplings and thick green moss that the chanterelles favoured. They grew low, partly covered by vegetation, like gold coins scattered on the weedy bottom of a lake.

She came to a sandy hollow, dappled with sunlight. It was one of her most reliable patches, and it took her only a few minutes to find the first chanterelle. The sight of the little golden disc made her heart leap, as though it had revealed itself especially for her.

She knelt down with flies circling her head and slid two fingers around the chanterelle. It was cool under the moss. The knife sliced easily through the stem.

Like an offering to the gods, she held the pale orange trumpet up to the light, closed her eyes and inhaled its scent of wet stone and old, sweet apples.

A noise close by startled her. She dropped the mushroom. Someone was laughing in disbelief, the laughter punctured by little gasps and screams.

Nej, nej, nej, nej,’ said a male voice.

Gudrun moved towards the sound, keeping her feet on the thick, slippery moss that silenced her steps, and taking care not to snap any twigs or branches. Her heart beat sickeningly fast.

Something red showed between the trees: an anorak. It bobbed up and down as the stranger darted to and fro, bending and standing.

And there was something else: the forest floor was virtually shimmering with gold. Even from where Gudrun was squatting behind a stunted pine, it was obvious that there were hundreds, perhaps thousands, of chanterelles in there.

She must have made a sound after all, because the man suddenly raised his head and swivelled around to look right at her.

He was young enough to have been her son, perhaps in his late thirties. His chubby cheeks were plum-coloured with excitement, his long, greying hair tousled and wild.

Hej,’ he said. Just like that, as though they were old friends.

This had a disarming effect on Gudrun. She felt herself softening towards him.

‘This is unbelievable, so many. Come.’ He waved. ‘Come and see.’

She didn’t want to, but something pulled her forward, as if by a rope tied around her waist.

As she pushed through the branches, she wondered if she was dreaming. If maybe the painkillers they had given her yesterday at the hospital were causing her to hallucinate.

Her eyes took in a rucksack, tossed aside in a patch of bare sand and next to it a clipboard with a few crumpled sheets of paper on it.

The man looked at her warmly. ‘I see you have the tools of the trade,’ he said, nodding at her basket. ‘A fellow mushroom hunter.’

She opened and closed her mouth like a cod, silenced by his forward manner.

‘Do you live locally?’ he asked.

She nodded feebly.

‘Then, if you don’t mind,’ he said, picking up the clipboard and taking down a pencil from behind his ear. ‘Could you tell me where else I might find chanterelles in this plantation?’

Gudrun noticed with alarm that the papers attached to the clipboard were photocopies of small-scale maps.

‘No, no, it’s not like that,’ the man said. ‘I won’t be picking them. It’s purely for scientific purposes – Aalborg University.’ He fished an ID card out of his pocket.

Gudrun stared at it, marvelling at the barefaced cheek of this Torben Larsen, Research Scientist, Department of Chemistry and Bioscience. She was still too astounded to speak.

She gave back the ID card and noticed that Torben Larsen hadn’t yet picked any chanterelles but instead filled two tiny specimen containers with moss and sand.

‘Perhaps it’s easier if you look at the map,’ he said, handing her the clipboard. ‘It’s local people like you who make all the difference. No amount of years in a laboratory could replace what you know.’

Gudrun thought of what the vicar had said earlier. Was this the sort of stranger he had had in mind?

‘Are you fond of chanterelles?’ she managed to stutter.

‘Oh, yes,’ he said. ‘My parents used to take me hunting for them. That’s what kicked all this off.’

‘All this?’ said Gudrun.

‘I’m trying to pinpoint the conditions in which chanterelles thrive. The exact type of soil they need, the required species of surrounding vegetation and so on. The more sites like this that I am able to study, the more I will know.’

She squinted at him. Torben Larsen had his back to the sunlight. It made his protruding ears look a luminous red, almost transparent.

‘You used the word “exact”,’ she said. ‘Of course, you must already know that there is no such thing as exact when it comes to chanterelles. They are free-spirited little things.’

‘Fantastic.’ He rushed over to the rucksack and retrieved a notebook. ‘The way you just put that.’ He repeated it to himself as he wrote: ‘Free-spirited little things.’

Gudrun meanwhile looked at the map, easily picking out the main road and the neat grid of tracks on either side of it. Torben Larsen came back and passed her the pencil. ‘You can outline the patches with this, if you like.’

She shook her head vigorously. ‘No maps. Nothing must ever be committed to paper.’

‘Right you are,’ Torben Larsen said, tapping the side of his nose. ‘Good point, um …’

‘Gudrun Holm.’

‘Good point, Mrs Holm. You never know what hands such information might fall into.’

She looked up at him. ‘Precisely, and it’s Miss Holm,’ she said, before making a momentous decision.

She took a deep breath. ‘But I could point them out to you, if you like?’

For a moment, she considered confiding in him that she was dying, but something stopped her, something that had been niggling away at the back of her mind, a question.

‘Before I do,’ she said. ‘Tell me, why do you need to know so much?’

Torben Larsen looked sheepish and excited at the same time. He lowered his voice. ‘I wasn’t going to say anything, but I think I can trust you. One secret deserves another, right?’

‘Trust me with what?’ Gudrun said, narrowing her eyes.

He held up his thumb and index finger, a centimetre apart. ‘I’m about this close to a huge breakthrough, Miss Holm, something that has eluded scientists for years.’

He bent down and carefully picked a chanterelle.

‘Soon,’ he said. ‘Beauties like this will be cultivated in greenhouses and polytunnels all over the world, thanks to what I’ve discovered.’

The clipboard became butter in Gudrun’s hands, sliding out of her grip and landing on a heap of pinecones. Her nausea returned. She waved her hands helplessly in front of her chest.

‘They will be on the menu of every restaurant and on everybody’s lips. They will conquer the world,’ Torben Larsen said, blind to her distress.

Gudrun found her voice. It was whinging and weak. ‘But it’s impossible,’ she said. ‘People have tried, of course, but chanterelles are too fussy. It will never take off.’

‘Oh yes it will. I’m almost certain I have found a way to mimic the symbiotic relationship between these fungi and tree roots under laboratory conditions,’ Torben Larsen said, his eyes shining with a strange, brilliant light.

He slapped Gudrun’s back, almost causing her to fall forward. She gasped for air, hands on her knees, swallowing bile.

‘I’m talking about mass production, Miss Holm, a brand new reliable food source. You will not need to pick these mushrooms ever again. You will be able to buy them in your local supermarket – fresh, tinned, frozen, freeze-dried, you name it. Isn’t it great?’

He laughed, mistaking her horror for amazement, her disgust for mock disbelief.

‘Stop,’ she said, pressing her hands to her ears. ‘In God’s name, stop.’

She looked wildly around the clearing. It had started to spin before her eyes, like a gold and green wheel. But Torben Larsen kept on laughing as though he had said the funniest thing.

His mouth was full of dark fillings, she saw now, and his nails were bitten right down to the peeling, bleeding skin. There were nicotine stains on the fingers of his right hand.

Her beautiful chanterelles. Torben Larsen would take them and rob them of their rarity, the very thing that made them special. The secret of the Holms would be of less consequence than a gull’s feather in a North Sea storm.

A purple dusk fell over her eyes. She gripped the mushroom knife in her pocket so tightly that it felt as though her veins would burst.

‘You stupid, stupid man!’ she screamed.

Torben Larsen fell heavily, still with a self-congratulatory smile on his lips. He clutched his anorak and looked down in surprise at the beetroot stain spreading across his chest. Then his eyes rolled back, starting unseeingly at the summer sky, while a bluebottle crawled across his face.

Gudrun pulled back the knife. There was a lot of blood. She wiped her boots on the bracken and buried her jumper in the sodden ground with Torben Larsen’s rucksack and papers. Nature would take care of his body. Not many people crossed the woods at Østvig, and by the time he was found, if ever, she would be long dead herself.

It was only when she neared the house that her legs began to tremble on the bike. The sun beat down on the tarmac and pearls of sweat ran down the back of her neck. It was windier now and the sea was up, getting noisier as she shortened the distance between herself and the beach.

When she got home, she would have a bath, then get under the cool covers of her bed, close her eyes and never rise again.

‘But what about the chanterelles?’ a little voice inside her insisted. ‘What will it all have been for, if you don’t tell anyone about them now?’

The local boy from earlier was back, poking the lyme grass with a stick as though trying to spike fish. She slowed down and looked at him more closely. There was something singular and wilful about him, something that reminded Gudrun of herself. Again, the vicar’s words came back to her.

She stopped and got off the bike.

‘You there,’ she cooed to him.

The boy looked up, his concentrated expression contorting into one of terror and alarm. He threw down his stick and hunched his shoulders.

‘Don’t be frightened,’ she said, wheeling the bike over to where he stood. ‘I won’t shout at you this time.’

The boy looked unconvinced. He was trembling, his dirty little hands balled into fists, his wide eyes fixed on a streak of blood on her thigh.

‘It’s nothing. I scratched myself on a branch. But listen to this,’ she said. ‘There is something I want to tell you, a secret.’

The boy looked at her warily, but she could tell that he was interested. No child had ever been born who didn’t like a secret.

‘It’s a good secret,’ she said. ‘The sort that people would do anything to steal from you, but you won’t let them. You will defend this secret with your life, even kill for it if you have to.’

‘Come,’ she said and made him sit down with her on a large white boulder by the side of the road. It was smooth and warm. She felt a great sense of peace spreading through her body.

‘Now,’ she said, very quietly, though only the crickets and adders and skylarks were around to hear them.

‘Do you know what a chanterelle is?’