I lie to Mum. Tell her Art peed on me. She's surprised - he's never been a wetter. She wants to change him. I tell her it's all right, I'll take care of it. I hurry to my bedroom and change my trousers. I'm almost out the door before I remember that Art should be changed too, so I quickly find clean clothes for him.

I consider telling Mum about Mrs. Egin's behaviour. Recall her threat - "slit your throat from your left ear to your right." Don't say a word.

The day passes uncomfortably. I can't forget what Mrs. Egin said, her wicked expression, stroking the pulsing patch of light. "You will see me die."

I should tell someone. It doesn't matter that she threatened me. She won't be able to sneak into my room if I tell someone and they lock her up like the mad old witch she is.

But I wet my trousers. If I tell about the rest, I'll have to tell about that too. And I don't want people knowing. So I say nothing. I pretend it didn't happen, that it doesn't matter. And all day long I feel as if a thousand eels of terror are wriggling around inside me.

Dad's talking with Mum about a craft fair when I come home. She's listening quietly, sitting by the piano. (It was in the house when we moved in - none of us can play.) She's frowning.

"This is one of the biggest fairs in the country," Dad says. "It's held every year, and a few of the Paskinston artists always go, representing the village. They sell a lot of work at it and rack up loads of orders. It's a real honour to be asked. It would be rude to refuse."

"But can't one of us go and one stay here?" Mum asks.

"Yes, but couples normally go together. It's not just about selling. There are hundreds of artists and interesting people there. It's a chance to meet, mingle, get to know other people. It'll be fun."

I hand Art to Mum and sit close to her, following the conversation. I learn a bit more about the fair, where it's held, who's going, how long they'll be gone for. Dad's proud to have been invited and keen to go, but Mum's worried about Art and me. She doesn't want to leave us alone. "Can't we take them along?" she asks.

"It's not the done thing," Dad says patiently. "Nobody else brings their kids."

Mum's frown deepens. We haven't been apart since we left the city, not for a single night. But if they go to the fair, they'll be gone for at least a week.

"They won't be by themselves," Dad says. "We'll leave them with one of the neighbours."

"I know, but..."

"Kernel doesn't mind. Do you, Kernel?" He smiles broadly at me, expecting my support. If this was yesterday, I'd have given it instantly. But Mrs. Egin's threat is fresh in my thoughts. I don't want to be left alone. So I just shrug in answer. "You OK, big guy?" Dad asks, surprised.

"Yeah."

"If you don't want us to go, just say. It's not that important."

"No. I mean, I don't mind. Not really. It's just..." I can't explain without telling them the truth. So again I shrug.

"What about Art?" Mum says, kissing his head, looking up at Dad.

"Art will be fine too," Dad says and he sounds a little impatient now.

"I'm not sure, Caspian."

"Melena..." Dad sighs. "Look, if it's going to be a big deal, we won't go. But this is our home now. We're safe here. I don't think we've anything to fear in this place. Do you?"

"No," Mum says quietly.

"So...?"

Mum pulls a face. "I just don't like being apart from my darling babies!" she exclaims. We all laugh at that, and everything's fine again. Mum bounces Art up and down on her knee. Dad smiles and hugs her. I feel happy and safe. I ask what's for dinner, and forget about the witch and all the bad thoughts of the day.

The morning of their departure. Dad gets the car ready while Mum takes Art and me over to Sally's house. Sally is one of the villagers who lives alone. A bit older than Mum. Fat. A great singer. She has two children of her own, but they've grown up and left.

"We're going to have a great time," Sally says as we set our bags down in the room where Art and I are staying.

"I wish there was a phone, so we could call and check that everything is all right," Mum grumbles. There aren't many phones in the village and Sally doesn't own one.

"Relax!" Sally laughs. "These boys can get along fine without you for a few days. Can't you, Kernel?"

"Sure," I smile. Mum smiles back, but shakily.

Dad calls us and we head out. He's standing by the car. The back seat and boot are filled with musical instruments and paintings. Two other couples have already left in a caravan with the majority of the pieces which they hope to sell. Dad hugs Art, then me.

"Look after your brother," Mum says, kissing my cheek.

"Of course he will," Dad says. "Kernel's the best brother in the world. He'll take care of Art better than you or I could."

Dad gets in and starts the engine. Mum hugs us one last time, then sits in beside him. And they're off. Art, Sally and I wave after them. Mum rolls down her window, leans out and waves back, until they turn a corner. Although Sally's right beside us, I can't help but think as they roll out of sight - we're alone now. Just Art and me. In a remote village. With a witch.

The day passes smoothly. School, playing with Art during lunch, dinner with Sally and some others. The villagers like to share meals. Here it's not polite to eat by yourself all the time. We often have guests over to eat with us, or go to a neighbour's house.

Art doesn't miss Mum and Dad. He eats, drinks, plays and behaves the same as always. Doesn't cry when Sally gives him a bath. He does give her a sharp nip on her left forearm at one stage, leaving deep marks, but that's normal for Art.

"We should stitch his lips together when he's not eating," Sally says, rubbing her arm. But she's only joking. Sally loves kids. Of course, she'd rather not be bitten, but the whole village knows about Art's biting habits. Sally knew what she was letting herself in for when she offered to have us.

It's strange not having Mum and Dad around. Things were different when we lived in the city. They often went out at night, leaving me with a babysitter. And they'd go for holidays by themselves occasionally. I didn't mind. I enjoyed staying with other people - I always got loads of treats.

But for the last year we've been together all the time. I've got used to them being at home every night. I feel like I did when I lost my favourite teddy bear a few years ago. It was a scruffy grey bear, nothing special, but I'd had it since I was a baby. It had been my constant companion, even when I'd outgrown my other teddies. I took it to bed, on holiday, even to the cinema. I felt like a friend had died when I lost it.

This is almost the same. Not as bad because I know Mum and Dad will come back. But strange. Like something's wrong with the world.

I'm uneasy when it's time for bed. Sally's spare bed is soft, but it smells damp, like my socks when they're wet. Art goes to sleep immediately, delighted to be sharing a bed with me. But I can't drop off. I'm tired - I woke early, knowing Mum and Dad were leaving - but my eyelids won't stay closed.

I think about Mrs. Egin. I haven't seen her since that morning when she witched out on me. I've taken the long way to school and back every day since. I've tried to laugh it off, make like it was no big deal. Told myself I imagined the curses and her stroking the patch of light.

But I know what I saw. I can't pretend it didn't happen. And although I'm not as scared as I was that first night, I'm still shaken, afraid to close my eyes in case she's there when I open them, standing over me, cackling, a knife to my throat.

I turn from my left side to my right, then back again. I try lying flat on my back, then on my stomach. Nothing works.

Annoyed, I stop trying to sleep, hoping I'll drift off by accident. I look round the small, cosy room, then focus on the patches of light. They look the same as ever, various shapes and shades. I count triangles, quadrangles, pentagons, sextants... No, that's an instrument. Sextuplet? I'm not sure. I think that's right, but I'm not... maybe it's a...

I wake suddenly. Hexagon! Of course. Can't believe I had trouble remembering that. The brain can play funny tricks when you're tired. I turn, yawning, looking for Art.

He isn't there.

At first, I think he's just slipped further down beneath the covers, but when I lift them there's no sign of him.

I sit up swiftly, sensing danger, recalling Mum's last words to me - "Look after your brother." Flash on an image of Mrs. Egin sneaking in, stealing Art, putting him in a big black pot and boiling him alive.

My world is never truly dark. The patches of light mean I can see pretty well even on the blackest night. Mum and Dad used to try to convince me that the lights weren't real, but if they're imaginary, why do I have such fantastic night vision?

I get out of bed and hurry to the door, so certain Art isn't in the room that my gaze glides right over him and I almost crash into him. Then my senses click in and I stop. Blink a couple of times to properly clear my eyes.

Art's in the middle of the room. There's a large patch of orange light pulsing just over his head. He's playing with marbles which Sally gave to me earlier. He's holding two of them up over his eyes. They're orange-coloured, like the light.

Art sees me and smiles, looking at me through the orange marbles. For a brief second I'm positive that somebody or something is in the room with us. I think I hear a soft growling noise. My head snaps left, then right - nothing. I look back at Art. In the strange orange light, with the marbles covering his eyes, he doesn't look like my brother. I start to think that it's not Art, that he's been replaced by some evil spirit, that the witch has been here. I feel afraid. I back up to the bed.

"Art?" I say, very softly. "Is that you? Are you OK?"

A giggle breaks the spell. Art lowers the marbles. And I see that of course it's him.

"Idiot!" I laugh weakly at myself. I go pick Art up and take the marbles away. Sally said not to let him have them in case he swallowed one. Art grumbles and tries to grab them back, but I tell him they're dangerous. He understands that and snuggles into me, nuzzling my shoulder with his teeth, but gently, not like when he bites somebody.

I stand there with Art, feeling cold but happy, smiling at how silly I was. Art falls asleep in my arms. I carry him back to bed, tuck him in, then climb in beside him. Lying on my side, I stare at the orange light, still pulsing. It seems to have grown bigger, but that's not unusual - the patches often change size.

I don't like this orange light. There's something creepy about it. It reminds me of the pink light which Mrs. Egin stroked. I turn my back on it and shut my eyes tight, trying to fall asleep again. But I can still sense it there, hanging in the cold night air, lighting up the room with its ominous orange glow. Pulsing.