For sixty-two years, Mary Murphy has lived in the bakers' shop in Camberwick Green. In her earliest memories, she sat on her father's work table passing him the ingredients; as a young woman, she raised her son here; now she is taking the day's leftovers from the window display. Although the inside of the shop has been fitted with glass-fronted cabinets and the coal-fired oven replaced with a large electric one, she has always gone to great pains to keep the outside looking just as it always has, with fresh paintwork every year.

Just as she turns the 'Open' sign to 'closed', a mobility scooter pulls up outside and an elderly man begins to disembark. She hurriedly steps outside to offer him an arm to lean on and to pass him his walking stick.

"Not late, am I?" he asks as he hobbles into the shop.

"Oh Peter, don't worry – I'll always stay open a few more minutes for you. You know that."

"Oh, you've got a new helper!" he remarks, nodding towards an auburn-haired teenage girl who is busy sweeping the floor.

"You remember my granddaughter, Michaela?" says Mary, "She's staying with me over the Summer, learning the ropes."

Peter beams at the girl. "Well, Michaela, I didn't recognise you – Though I should have done, There's a bit of your great-grandfather in your face. So you want to join the family business, eh?"

"Yeah," she replies, smiling awkwardly as she isn't completely sure she knows who this man is, "I really like it here. It's quiet."

"You know, that's the best news I've heard for a long time. There's not many of the old guard left now, not now the Honeymans have emigrated. I hope it all goes well for you, I really do."

"Erm – thanks."

"Anyway, Peter," says Mary, "What can I do for you?"

"I just need four white rolls, please."

"We have a few of those left," says Mary, and goes to fetch some tongs and a paper bag. "Why don't you try some of Michaela's walnut cake, too? You can have it for free, it'll go to waste otherwise. I need an expert to give it the taste test. Michaela, get that last slice of cake."

"I can't say no to that, can I?" says Peter, as the girl brings over a large plate with one slice of cake left on it. He examines it, smells it, takes a bite. He nods approvingly, and declares it a true Murphy walnut cake.

"Well," says Peter, "I'd better let you get on. I suppose you've got plans for the afternoon."

"I've promised her a walk out," replies Mary.

"Oh, are you going to look round Pippin Fort?"

"No, we went there yesterday. She wants to see the windmill."

"Oh, I see. Well, say hello to Windy for me."

"I will."

Peter says his goodbyes and trundles away on his scooter.

"Do you remember Peter?" Mary asks Michaela as she counts up the till.

"Was he the one who used to be the postman for years and years? And now he's married to the postmistress?"

"That's right."

"And once he punched my great-granddad in the face by accident."

"Ha! Yes, Dad was just opening the door as he was knocking on it."

Michaela struggles to picture the scene; although she is just a few feet away from the spot where the event happened, Peter will only appear in her mind as a very old man with bad knees and her great-grandfather in black and white.

"Nanna," she asks when she's finished sweeping, "do you want me to wash the big cake stand before we go out?"

"Just wait a moment."

Mary finishes counting the money in her hand and notes down the amount, then lifts a cake stand from the window display. Although the slices of cake has all been sold, it's still liberally dotted with crumbs and blobs of buttercream. Slowly, carefully, she takes a paper bag and tips all the crumbs into it. Michaela watches with interest, but doesn't say anything as he grandmother twists up the top of the bag and places it next to the till.

"Now you can wash up. I'll pack us a bag, we'll need some drinks on a warm day like this."

By mid afternoon, grandmother and granddaughter are setting off on their walk. It's a warm sunny day with very little breeze, so they're both dressed in shorts and t-shirts. Mary leads the way, carrying her backpack, pointing out interesting buildings and giving a short history of each one – the wedding dress shop that used to be a fishmonger's, the holiday flats that used to be the doctor's house, and so on. Michaela isn't all that interested, she's heard most of it before, but she nods along politely and works on memorising her recipes.

After a few minutes walking down the main road, Mary leads her granddaughter through a gap in the hedge. They clamber over a stile and along a path paved with large stone blocks, well worn by hikers and birdwatchers, that runs though farmland and begins to climb a hill. The conversation turns to the possibility of getting the old van fixed up and back on the road as a mobile sandwich shop that could be parked up at the tourist hotspots, a plan that Mary has been considering for several years on and off and Michaela is quite enthusiastic about, occasionally interrupted by passing walkers exchanging pleasantries.

At the top of the hill, they sit down on the grass to rest and admire the view. The hedgerows stretching away into the valley, down towards Camberwick Green; the main road, sweeping through the landscape towards Trumpton; and in the opposite direction, on top of the next hill, is the tall conical structure of the windmill, silhouetted against the bright sky.

Mary unzips the bag and passes Michaela a bottle of pop and an apple. The girl notices the little paper bag of crumbs that her grandmother collected from the cake stand. She opens her mouth to ask what they're for, then decides that there's probably a very obvious reason to bring them along, and the question might sound a little stupid.

"Hm? Did you want to say something, my love?" asks Mary.

"Oh no, I just- I was wondering what those buildings down there were, that's all." Michaela gestures towards a cluster of large white buildings further down the valley, almost blindingly bright in the hot sun.

"Those? That's some warehouses and things. It's called Bell's Farm Industrial Estate. You won't remember Farmer Bell, he sold up and retired long before you were born, but the land still has his name. I bet he loves that, if he's still alive!"

There's a note of spite in her voice that makes Michaela curious enough to ask why.

"Oh, he was just..." Mary begins, then pauses and sighs before carrying on. "He was... smug. Up himself. The more money he had, the more land he owned, the worse he got. He ended up falling out with a lot of people, they got so sick of him going on and on about all the expensive things he'd bought and all the business he was doing. But I don't know that it bothered him. He probably thought we were jealous."

A long silence. Mary takes a bite of her apple, crunches it, and takes another; though Michaela can tell she hasn't finished her story. She picks a dock leaf to use as a fan while she waits – it's not much, but at least it's something. In the distance an intense speck of sunlight hitches a lift on a car travelling along the main road, then hops onto one travelling in the opposite direction before diminishing and fizzling out altogether.

"...And he kept battery hens, of course," Mary continues in a lower voice, as if someone with malicious intent could be listening in, "I went to do some work for him for a while when I was your sort of age, for a bit of pocket money, you know – but those poor hens. Crushed into little cages all their lives. He told me that was what they had to do to keep prices down and it was the way of the world. I couldn't look at him the same way again. I know you can't be sentimental about farm animals, but that was just too much for me. I told him to stuff his job, and I went home and cried. That's why I always use free range, even though they're more expensive."

"Oh, right. No, I don't like battery eggs either."

"Shall we get going?" says Mary, as she throws her apple core into the long grass.

"Yeah, OK."

Mary opens the backpack again to replace the half-empty pop bottles. As she does so, she lifts out the little bag of crumbs and places it on top of everything else. Michaela can contain her curiosity no longer.

"Nanna, I know this might be a stupid question, but what are you carrying those crumbs around for?"

"These? Oh, they're for Windy Miller." Mary swings the pack up onto her back and leads the way to a gap in the nearby hedgerow. Stretching down along the edge of the following field is a path less well-used that the one they'd walked up on, a strip of compacted soil edged with waist-high grass and weeds.

"Windy Miller?" asks Michaela, trotting to keep up, "I thought he'd died years and years ago?"

"I wouldn't have thought you remembered him, to be honest. You could only have been two or three when you last saw him."

"Not really, but my dad mentioned him a few times. He said that once when I was a baby we came to visit and I wouldn't stop crying, so they passed me to Windy Miller and I just went straight to sleep. And everyone went on about it like it was a miracle or something. I'm not sure who he was though. He sounds like one of Uncle Paddy's old hippy friends."

"Oh, he was everybody's friend. We all loved him. I used to think of him as a sort of adopted granddad. I used to come this way a lot, I used to visit him all the time."

"Oh right, he lived in the windmill?"

"That's right. All his life. Even when he was ninety, he wouldn't leave that old mill. No electricity, no running water. Everyone in the village offered to give him a space in their house, he wouldn't have it. We all came up to help him out of course, draw some water up from the well for him, lug a few sacks of corn around, that sort of thing. We couldn't see him go without, not after all he'd done for us over the years." She smiles wistfully.

"But – he's dead now, yeah?"

"I don't like to think of it like that."

"You're taking the crumbs to his grave, though?"

"Hah! Peter was right, there is some of my dad in you. He always had to be the sceptic. 'Earth-bound', Paddy would say."

Michaela isn't sure if this is a compliment or admonishment, so she says nothing more and follows her grandmother down to the far end of the field, where there's a kissing gate leading through to a narrow lane.

"Hardly anyone uses this road nowadays," says Mary, "just tractors, really. Everyone else goes down the main road."

"It looks quite steep."

"My dad's van used to struggle a bit, if it was fully loaded. I don't know how Windy used to do it on his little tricycle. Imagine trying to pedal up here, ninety years old."

As they draw closer to the mill, it becomes obvious that it's been derelict for quite some time. One of the sails has snapped in half, another is missing altogether; the remaining two are reduced to skeletal frames that stick out like a scarecrow's arms. The pinkish rendering has cracked and flaked off in chunks, and is stained with so much moss and rust that it almost looks like tree bark. The door has rotted off its hinges, revealing a cavern lined with leaf-litter and birds' nests. The cogs and shafts of the mill have corroded into one immovable mass. The little granary has a large hole in the roof through which pours a mass of brambles, curved and twisting like the spray of a fountain.

"This was all his land here," says Mary, gesturing down the more gentle slope on the far side of the hill, "he was almost self-sufficient for a long time."

She points out where the animal shelters were, now piles of planks and corrugated tin crumbling away in the undergrowth. She shows her granddaughter the orchard, now a little woodland. They walk down to the duck pond, muddy and overgrown but still home to a few birds. Michaela follows and listens reverentially, feeling as if the ground is a place of worship and her grandmother's memories of visiting the old miller are parables. Five o'clock comes and goes. A pigeon coos from an apple tree, the sound carrying hundreds of yards in the still air.

"Well," sighs Mary at last, "if we're going to give Windy his cake, we might have to whistle for him."

"Nanna, that makes no sense at all. Is it like one of those magic spell things that Uncle Paddy gets us doing?"

"Ha! Kind of. Come on, I'll show you. Back up to the top of the hill."

"But what do you mean by 'giving him the cake'? Are we going to throw it on his grave, or what?"

"No, no! He wasn't buried. We scattered his ashes up here. We're going to throw the crumbs into the wind. I mean, it's just symbolic, but – you know, it makes me feel better. It's like leaving flowers, but he was a cake fiend, so that's what I bring. I don't know how one person could get through as much cake as old Windy did."

"Okay, that makes sense. There's no wind to throw it into, though."

"That's why we need to whistle for it."

"I really don't understand, Nanna."

"I'll show you."

By now the pair are back by the windmill. Even up on the high ground, only the faintest breath of breeze is drifting across the landscape; not enough to stir the locks of hair falling over the girl's face. Still, Mary takes the little paper bag from her backpack and tips half the crumbs into her palm and half into her granddaughter's.

"Do I through them in the air, or what?" asks Michaela.

"No, we whistle for the wind!" Mary replies, a little impatiently. "This was the first trick that Windy ever showed us. When you need the wind to blow, you whistle for it. Like this..."

She whistles one long, low note and then a higher one. Nothing happens. She tries again, and again. Nothing goes on happening.

"We need more. You try."

"What do you want me to do? Just whistle?"

"That's right, like this."

Glad that no-one is around to hear her but still feeling very foolish and confused, the girl copies her grandmother. Again, nothing happens.

"Come on, again!"

"Again?!"

Just as Michaela expected, the effect of her second whistle is precisely nothing. And the more they both whistle, the more nothing happens. The coolness on her sweaty skin is just that the evening sun isn't quite as strong as it was. Her hair is only fluttering over her face because her head is moving a little. The rustling in the trees around can only be birds hopping around. It must be! But the long grass in the fields below is graduating from gloss to matte and back again as it ripples under some invisible force that comes rushing up the hillside, sweeping past their faces as if they're standing in the path of a fan, lifting the piles of crumbs from their upturned palms and sending them spiralling into the sky and out of sight.

"Hello, Windy Miller," Mary whispers as the gust dissipates into the ether.