Lucy bent to smell the scent of a rose, but was startled when a fairy leapt out of the flower. Oh. No, not a fairy, but a bee. The bee hung in the air in front of Lucy’s face as if it were wondering if she was a flower. Then, the moment of mutual misidentification over, it flew away.

‘Why did I think it was a fairy?’ Lucy asked herself. ‘What’s the matter with me?’

There had been something wrong for a while now. Things seen out of the corner her eye, strange things — an unexpected small person, and emerald snake rearing up, a cat in the corner of the room — but when she turned to look there was either nothing there at all, or only shadows, a twist of leaves, branches fluttering. Even so, she was left with an odd feeling that there had really been a presence until she turned her full attention to it.

That evening she was reading a rather dull book. Her mind, and then her eyes, wandered away from the text. As she was thinking of something else, she saw at the edge of her vision a large black spider detach itself from the printed words and begin to walk over the white page. Resisting the urge to scream and throw the book across the room, she watched the progress of the spider without looking directly at it.

It moved up the page, walked along a line of text, then settled down on one particular word, seeming to melt into the ink. Lucy looked to see what the word was.

Spider.

She put the book down and walked away from it. In the kitchen she poured herself a glass of wine and contemplated the idea that she was suffering the onset of schizophrenia or some other psychosis. Not liking the idea at all, she preferred to think that she had noticed the word, spider, on the next page and her unruly imagination had conjured up the hallucination of an actual spider for her.

So it went on. Day after day, improbable creatures appeared in the edges of her vision. Lucy stopped trying to look at them directly, instead observing by pretending not to notice them as they danced or loomed or lurked.

Then, a real cat turned up at her door. It was fearful at first, but she began to feed it and eventually it decided to move in with her, when she named it Henry, for no good reason, and began to think of it as a person, he.

The phantom cat shape appeared in her vision on evening as she sat watching TV with Henry. He noticed it, too. He sat up, flattened his ears against his skull and hissed right at the corner where the shadow cat sat. It vanished.

It was both comforting and disconcerting that Henry saw it. Comforting because it meant that she was not suffering from the onset of mental illness: Disconcerting because it meant that she was seeing things that were actually there.

The next time she mistook a bee for a fairy she looked at it straight on and said, ‘I know what you are.’ But it turned out that she did not. The creature dropped its bee disguise and she saw a peculiar twig-limbed winged creature. It buzzed angrily, gave her a small, but eye-watering smack on the nose, and flew away.

Henry had followed the whole encounter, and as the creature flew past him he leapt, like the predator he was, and caught the creature in mid air. He came to earth with it crumpled under his paws and leaned down, teeth bared.

‘No,’ said Lucy, ‘No, no.’

She prized Henry’s paws off his quarry and scooped it up. It looked like a collection of tiny sticks with a pair of transparent wings and a small, angry face.

‘I’m sorry,’ she said, and took it to the nearest tree where she laid it in the crook of a branch and watched until it recovered enough to fly away.

Lucy knew that if she kept on seeing these out of the ordinary beings, she would not be fit for normal society. People would notice, even if she never admitted a thing. So she refused to believe in their existence, even when Henry clearly saw them too. Gradually, with much practise, Lucy made them fade back into the usual world, to become shadows and nothing more. She was sad, but there really is no room for magical things in the everyday human world. Henry continued to chase shadows, but hardly ever caught them.