One midsummer night a fine new foal was born, just as a cold-coffee coloured crack of daylight appeared along the eastern ridge of the valley. At eight in the morning the foal was standing trembling beside his mother, drawing strength from the sun as she nuzzled and licked him into shape.

On his white flank was a grey patch, and the patch was the shape of a monk – as plain as if it was a drawing in a book. There was his smooth pate, the ring of his tonsure, his learned nose, round belly, hurrying sandaled feet, and knotted girdle flapping behind.

The first villager to see it was the milkmaid as she drove the cows back to the pasture. She laughed and clapped her hands excitedly. After she’d turned the cows into their field, she ran and knocked on the farmhouse door. “Come and see! Sally’s had her foal, and he’s a very special fellow, I’d say.” The farmer and his sons thoroughly cleared their plates of bread and dripping before they came to sort out their boots from the pile in the porch. They ambled down the lane wiping the crumbs from their mouths, bathing in the warmth of the morning on their faces. The foal was feeding, his long pins splayed out in the dewy grass. The remarkable patch was pressed against his mother’s side, so the men couldn’t see it.

“He’s a good’un, but what’s so special?” grumbled the farmer. They were about to leave when the mare shifted and the foal followed, showing his other side.

“Mercy! That is a thing!” cried the eldest son. “Do you see? A fat monk!”

And they all agreed.

“Now then,” said the middle son. “This will be our fortune. People will pay to see such a wonder.”

“So they will,” said the father, “but Father Gerald will not approve of such commerce. If it’s a holy sign he’ll make us show it off for nothing.”

“Then,” said the eldest, “we should sell him to the fair-man, for a good price.”

“And keep him hidden until the fair-man comes round”, said the middle son.

“And hide his mother too?” said the youngest. “There’s no need for that. I’ll just paint lime-wash over the picture.” And so he did.

When the milkmaid brought her mother to see the wonderful foal, she was naturally confounded that he had no special mark. They spoke to the farmer, who told her that she must have imagined it, whereupon her mother scolded her for being dizzy. But the mother was alarmed, as her daughter had never been dizzy before, and the daughter wondered if she was going mad, and together they decided she had better go into the convent to help the nuns and be looked after by them.

It happened that the fair came to the village the very next month, but the foal so young could not be removed from his mother, so nothing was said, and the youngest son kept secretly applying fresh limewash over the old to keep the picture well hidden.

It was three months before the fair came round again, later, at All Hallows. The farmer took the fair-man aside and asked him to come to the field late at night, when the rest of the villagers were making merry at the fair, to see something amazing. The three sons were waiting with a bucket of water, a scrubbing brush and a lantern; Sally was tied up and the foal bridled. The youngest set to work, scrubbing off the limewash. It was a lot of work, scrubbing off all those coats of white. After half an hour, the fair-man was getting restless and chilly. But surely, they must be getting near to revealing the secret. The other sons took turns to scrub.

After an hour the sons were all exhausted and the foal too, by his furious kicking.

The fair-man stormed off up the lane cursing them for wasting his time. He began to worry that they’d deliberately got him out of the way while some mischief was done to his precious caravan, so he was much relieved to find it all secure.

The farmer and his sons went dejected to bed. Not only had they failed to make money from the foal but they’d missed all the revelry of All Hallows Eve as well.

The next morning, as soon as it was light, the farmer went again to see the foal. It was quite clear that all the paint had gone and yet the foal’s flank was plain white where the monk had been.

It was now All Saints Day and the priest was ready to hear confessions in the church. The farmer was the first to come in. “Father Gerald, I’ve perhaps done a bad thing and been punished already.” And he explained the whole matter.

Father Gerald, having given it careful consideration, said; “My son, you have been foolish rather than sinful. And while the picture of the monk may have been an accident of nature, its disappearance is a true miracle that must be made known to the whole world!”

So they began to show off the foal, and everyone who saw it marvelled at its pure white flank, given that it had once had a remarkable representation of a monk on it, which they could only imagine. And although the farmer dare not charge anyone to see the foal, the many that came from far off wanted food and drink, and sometimes lodging, so there was money to be fairly made from that.

But one day a horseman came with a letter for Father Gerald. It was from a clever clerk at the Abbey, and said, in Latin of course, “How do you know that the foal ever had the picture on it? It might have been born white, and then where’s your miracle?”

Father Gerald confronted the farmer and his sons. “We’d not lie to you, Father! But anyway, Jenny the milkmaid saw it first. You’ll believe her, won’t you?” And certainly he would, because Jenny had always been known for her good character.

So Father Gerald invited the clever clerk to accompany him to the convent to see her, and the clerk suggested they take the foal too.

Jenny was looking out of the window when the priest came across the courtyard, and she thought “He’s brought that foal, and the picture on its flank has reappeared!” She was delighted. But really it was just the little clerk, in his monk’s habit, hurrying along beside the foal. But then the priest tied up the animal, and the picture appeared to come to life and walk off the foal’s flank as the clerk strode into the hall and stood before her. She began to shriek with terror, and could not stop.

The clerk took the priest outside and far away from the terrible noise. “This is the work of the devil, not a holy miracle,” he said. And he went back to the Abbey and wrote to the Holy Father in Rome to denounce them all.

Meanwhile, Jenny’s shrieking had caused the horse to buck and rear in fright, and its tether came loose. Away it ran onto the moors, where there were many other white foals, so no-one could ever tell which one it was, whether they believed it was affected by Good or Evil or neither.

It was many months before the clerk received a reply from a high-ranking scholar-priest in the Vatican. “Dear Brother, your letter led me to conduct certain experiments with limewash and I have found that in sufficient concentration it invariably causes the colour to bleach out of horses’ hair.”