This is the scariest story I have ever heard. It was told to me by another boy, back in the mid nineties. We were on a school camping trip near Crickhowell in central Wales. The campsite is in the grounds of an old chapel, on a triangle of grass, turned to mud by the Welsh weather and the walking boots of two dozen boys. A small brook surrounds the chapel on two sides, and the road – a single track, with huge earth banks either side – forms the third. Two school minibuses are parked just off road, inside the single gate to the chapel. A few trees run down towards the brook. On the other side, a hill rises steeply. It is planted thickly with trees – not so thick that it’s not perfect for playing kidnappers, but thick enough that if you wander too far into the woods you can lose track of the chapel – only the downward slope points you back in the right general direction. At the back of the chapel, four huge logs form a square bench around a camp fire, and that’s where We’d had a supper of sausages, beans and hot, strong tea, brewed inside the chapel in its rudimentary kitchen with its huge steel water tank.

After dinner, when the teachers decide it’s time to go to the pub, the boys are sent to our tents. There are ten of us in each: a row of five sleeping bags either side. For most of us, this is a rare treat. New walking boots and rucksacks, freshly-bought sleeping mats from Blacks or Millets. We’re in our sleeping bags, but this is an adventure and no-one is ready for sleep yet. We talk, I don’t remember about what. The hills, tomorrow’s walk, the teachers. At some point, someone suggests ghost stories. Everyone agrees: no-one wants to be the coward.

The first or second stories are bland, ‘Boo!’ kind of things. Fun, but nothing disturbing. Nothing to scare you. Then someone pipes up, ‘I know a true story. My brother heard it. It happened a few years ago, in Dartmoor. There’s a big prison there, in the middle of the moors, where they put mad people, psychos that kind of thing.

‘Anyway, there’s this boy and his girlfriend driving in the car. It’s night time, and it’s raining. Just like tonight. They’re listening to the radio, and this news flash comes on: “Anyone in the Dartmoor area, be aware that a prisoner has escaped from Dartmoor Prison. He is very dangerous. Do not approach him, call the police.”

‘So obviously the girl is really scared, but the boy reassures her, “We’re miles away from Dartmoor prison, nothing’s going to happen. Soon we’ll be at the hotel.”‘

At this point, all the boys in the tent are quiet. No shuffling, we’re all fascinated where this is going.

‘Anyway, the car breaks down, and they’re in the middle of nowhere on this country road. It’s absolutely pitch black. The guy doesn’t know what’s wrong with it, and he says he’s going to have to go and get help. The girlis really scared, she doesn’t want to be left on her own in the car, but the boy says he saw a house about two miles back down the road, he’ll go there, call the AA, and then come back for her. She wants to go with him, she’s begging to go with him, but he says it’s wet and dark and he doesn’t want her to get cold. She’s to lock the doors once he gets out of the car, and stay there till he gets back.

‘So off he goes, and she locks the doors. She gets a blanket off the back seat and she turns on the radio. Just music. The news comes on again and there’s the same report about the escaped prisoner. But there’s a bit more information. He was a mad butcher, and he killed everyone in his family with a meat cleaver. Chopped them up into pieces. The girl is obviously really scared, but she remembers the prison is miles away, and Dartmoor is a huge, empty place and the chances of the lunatic being nearby are remote.

‘At some point, she starts to nod off. But something wakes her up. A tapping noise *tap tap tap*.’

At this point the narrator makes the point by tapping a torch on the ground. *Tap tap tap*

‘Where’s the noise coming from? She’s really scared and she turns off the radio. She can’t hear anything. She peers out of the window, but it’s just dark outside, and the windows are covered in rain. There’s no one there. She checks that the doors are locked and they are. Must just be her imagination, she thinks. She turns the radio back on and pulls the blanket a bit tighter.

‘But as she starts to drop off she hears it again: *tap tap tap*. Except it’s louder this time, and she isn’t imaging it. She turns the radio off again and looks out into the night, but there’s nothing there. But she can still hear *tap tap tap*. And now she’s really freaking out, She turns everything in the car off, and she crawls into the footwell, and she pulls the blanket over her head and she can still hear *tap tap tap*, *tap tap tap*.

‘At some point, she falls asleep because she’s absolutely exhausted and really scared. When she wakes up she hears *tap tap tap* really loudly. *Tap tap tap*. She pulls the blanket off from over her head and she can see it’s daylight outside, and she’s scared to look, but she does. *Tap tap tap* – it’s a man in a police uniform knocking on the car window. He sees her and he says to her, “Get out of the car.”

‘She’s scared and she shakes her head, but the policeman keeps telling her to get out, and eventually she reaches up and unlocks the door and he opens it and he says to her, “Get out of the car.” She does, and he takes her by the arm and he says, “Are you ok?” and she tells him what happened about the car breaking down and her boyfriend going off to get help and not coming back, and all the time the policeman is looking at her and he’s kind of pulling her along with him, and she says, “Where are you taking me?” and he says, “Come on, just keep walking. Keep looking at me and keep walking.” And then she realises she can still hear *tap tap tap*.

‘And she says, “Why, what’s happening?” but the policeman just keeps saying, “Walk with me, come on, keep talking to me, keep looking at me.” And she can see he’s taking her towards a police car and there is another policeman there, and now she’s really scared and she tries to turn around and the policeman is nearly shouting now, “Just keep walking with me, don’t look back.”

‘But she looks back and she can see a man in a white gown squatting on the top of the car, and in his hand he’s got something and he’s bouncing it on the top of the car *tap tap tap*. And she thinks, ‘What’s he got?’ and then she sees it’s the head of her boyfriend, cut right off, and the man keeps bouncing it on the top of the car *tap tap tap* and she screams and he looks at her and he smiles and he just keeps on tapping the head on the roof of the car.’

Well, by now you could hear a pin drop in the tent, and the narrator finishes. ‘It’s all true. He found a meat cleaver in the house down the road and he murdered the people there then he killed the boyfriend and then he found the car.’

Silence. No-once can top that. Torches are turned off and we all lie in our sleeping bags. I’ve been desperate to pee for at least half an hour, probably too much strong tea with dinner, but truthfully, I don’t want to leave the tent. There’s no way I’m going to make it through the night, though, and at some stage I crawl out of my bag, pull on some shoes, and go into the night.

There’s one toilet in the chapel, but for peeing you have to go in the trees by the brook. I make my way past the parked minibuses, and towards the trees. I daren’t look either way. The earth banks mean the road is just a black hole. The camp fire is out, so the only light is from the moon. I don’t want to be here. If I could close my eyes, I would, but it’s not an option. I find a spot by the first tree, and I start. I will not look across the brook and into the woods. I don’t know what I might see there. A flash of white? A face, smiling wildly at me? These are the longest minutes of my life. I will not look back as I rush back towards the tent. I cannot hear a tap tap tap on the top of the minibus, or a throaty, wet chuckle as I race for my life towards the safety of the group and crawl into my sleeping bag, heart racing. It’s a long time before I sleep.