Miss Lippetts shot me a look as we chanted, 'Good afternoon, Miss Lippetts.' So swift and crafty it was almost not there, but it was. 'Sit down, 3KM. Pencil cases out, please. Today, we'll exercise our supple young minds on a composition, on this theme...' As we got our stuff out, Miss Lippetts wrote on the board.

A SECRET.The slap and slide of chalk's a reassuring sound.

'Tamsin, do me the honour, please.'

Tamsin Murrell read, '"A secret", miss.'

'Thank you. But what is a secret?'

It takes everyone a bit of time to get going after lunch.

'Well, say, is a secret a thing you can see? Touch?'

Avril Bredon put her hand up.

'Avril?'

'A secret's a piece of information that not everybody knows.'

'Good. A piece of information that not everyone knows. Information about...who? You? Somebody else? Something? All of these?'

After a gap, a few kids murmured, 'All of these.'

'Yes, I'd say so too. But ask yourselves this. Is a secret a secret if it isn't true?'

That was a tight knot of a question. Miss Lippetts wrote, MISS LIPPETTS IS NANCY REAGAN.Most of the girls laughed.

'If I asked you to stay behind after class, waited till we were alone and then whispered, in all seriousness, this statement, would you go, "No! Really! Wow! What a secret!" Duncan?'

Duncan Priest had his hand up. 'I'd phone Little Malvern Loonybin, miss. Book you a room with a nice mattress. On all the walls.' Duncan Priest's small fan club laughed. 'That's not a secret, miss! It's just the gibberish of an utter nutter.'

'A pithy and rhyming assessment, thank you. As Duncan says, so-called "secrets" that are palpably false cannot be considered secrets. If enough people believed I was Nancy Reagan, that might cause me problems, but we still couldn't really think of it as a "secret", could we? More of a mass delusion. Can anyone tell me what a mass delusion is? Alastair?'

'I heard loads of Americans think Elvis Presley is still alive.'

'Fine example. However, I'm now going to let you in on a secret about myself which is true. It's a touch embarrassing, so please don't spread it around at break-time...'

MISS LIPPETTS IS AN AXE-MURDERER.Now half the boys laughed too.

'Shhh! I buried my victims under the M50. So there's no evidence. No suspicion. But is this secret still a secret? If it's one that nobody, and I mean nobody, has the faintest suspicion about?'

An interested silence played itself out.

'Yes...' muttered a few kids as a few kids muttered, 'No...'

'You'd know, miss.' Clive Pike raised his hand. 'If you really were an axe-murderer. So you can't say nobody knows it.'

'Not if Miss was a schizophrenic axe-murderer,' Duncan Priest told him. 'Who never remembers the crimes she commits. She might just...turn, like that, chop you to bits for forgetting your homework, whack splurt splatter, flush the remains down the sewers, black out, then wake up again as mild-mannered Miss Lippetts, English teacher, go, "Gosh, blood on my clothes again? How odd that this keeps happening whenever there's a full moon. Oh well. Into the washing machine." Then it would be a secret nobody knew, right?'

'Delicious imagery, Duncan, thank you. But imagine all the murders to have ever occurred in the Severn Valley, since, say, Roman times. All those victims, all those murderers, dead and turned to dust. Can those violent acts, which no one, remember, has thought about for a thousand years, also be called "secrets"? Holly?'

'Not secrets, miss,' said Holly Deblin. 'Just...lost information.'

'Sure. So can we agree, a secret needs a human agency to know it, or at least write it down? A holder. A keeper. Emma Ramping! What are you whispering to Abigail?'

'Miss?'

'Stand up, please, Emma.'

Worried, lanky Emma Ramping stood up.

'I'm conducting a lesson here. What are you telling Abigail?'

Emma Ramping hid behind a very sorry face.

'Is it a piece of information that not everybody knows?'

'Yes, miss.'

'Speak up, Emma, so the groundlings can hear you!'

'Yes, miss.'

'Aha. So you were confiding a secret to Abigail?'

Emma Ramping reluctantly nodded.

'How topical. Well, why not share this secret with us? Now. In a nice loud voice.'

Emma Ramping began blushing, miserably.

'I'll do you a deal, Emma. I'll let you off the hook if you just explain why you're happy sharing your secret with Abigail, but not the rest of us.'

'Because...I don't want everyone to know, miss.'

'Emma is telling us something about secrets, 3KM. Thank you, Emma, be seated and sin no more. How do you kill a secret?'

Leon Cutler stuck up his hand. 'Tell people.'

'Yes, Leon. But how many people? Emma told Abigail her secret, but that didn't kill it, did it? How many people have to be in the know before the secret's an ex-secret?'

'Enough,' Duncan Priest said, 'to get you sent to the electric chair, miss. For being an axe-murderer, I mean.'

'Who can reconstruct Duncan's glorious wit into a general principle? How many people does it take to kill a secret? David?'

'As many,' David Ockeridge thought about it, 'as it takes, miss.'

'As it takes to do what? Avril?'

'As it takes to change,' Avril Bredon frowned, 'whatever it is the secret's about. Miss.'

'Solid reasoning, 3KM. Maybe the future is in safe hands, after all. If Emma told us what she told Abigail, that secret would be dead. If my murders are exposed in the Malvern Gazetteer, I'm...well, dead, if Duncan's on the jury, anyway. The scale is different, but the principle is the same. Now, my next question is the one that truly intrigues me because I'm not sure what the answer is. Which secrets should be made public? And which shouldn't?'

That question had no quick takers.

For the fiftieth or hundredth time that day I thought of Ross Wilcox.

'Who can tell me what this word means?'

ETHICS.

Chalk mist falls in the wakes of words.

I'd looked 'ethics' up once. It crops up in the Chronicles of Thomas Covenant books. It means morality. Mark Badbury already had his hand up.

'Mark?'

'The answer's in what you just said, miss. Ethics is to do with what you should and shouldn't do.'

'Very smart answer, Mark. In Socrates' Greece they would have considered you a fine rhetorician. Is it ethical to get every secret out in the open?'

Duncan Priest cleared his throat. 'Seems pretty ethical to get your secret out in the open, miss. To stop innocent schoolkids being chopped up.'

'Spot on, Duncan. But would you spill the beans on this one?'

BATMAN'S REAL NAME IS BRUCE WAYNE.

Most of the boys in the class let out murmurs of admiration.

'If this secret gets out, what is every master criminal in the world going to do? Christopher?'

'Blow Bruce Wayne's mansion to smithereens, miss.' Christopher Twyford sighed. 'No more Caped Crusader.'

'Which would be a loss to society at large, yes? So sometimes it's ethical not to reveal a secret. Nicholas?'

'Like the Official Secrets Act.' Nicholas Briar usually doesn't say a word in class. 'When the Falklands War was on.'

'Just so, Nicholas. Loose lips sink ships. Now. Think about your own secrets.' (The connection between Ross Wilcox's wallet and his lost leg. My grandfather's smashed-up Omega Seamaster. Madame Crommelynck.) 'How quiet it has suddenly become. Right, are all your secrets of the "Yes, I Should Tell" or "No, I shouldn't Tell" varieties? Or is there a third category that, ethically speaking, is not so clear cut? Personal secrets that don't affect anyone else? Trivial ones? Complex ones, with uncertain consequences if you tell them?'

Mumbled Yeses, growing in strength.

Miss Lippetts got a fresh stick from a box of chalk. 'You acquire more of these ambiguous secrets as you age, 3KM. Not less. Get used to them. Who can guess why I'm writing this word...'

REPUTATION.

'Jason?'

3KM turned into a radiotelescope aimed at the class grass.

'Reputation is what gets damaged, miss, once a secret's out. Your reputation as a teacher'd be shot to bits, if it's proved you are an axe-murderer. Bruce Wayne's reputation as this wouldn't-say-boo-to-a-goose Mr Nobody'd be done for. It's like Neal Brose, too, isn't it?' (If I can grind a solar-powered calculator to bits then stuff this rule that I should be ashamed for grassing on a kid and getting him expelled. In fact stuff all rules.) 'He had quite a secret going, didn't he? Wayne Nashend knew, Anthony Little knew. A few others.' Gary Drake, over to my left, stared straight ahead. 'But once his secret is out, his reputation as this...'

To everyone's surprise, Miss Lippetts suggested, 'Golden boy?'

'Golden boy. Excellent term, Miss Lippetts.' (For the first time in God knows how long I earnt some class laughs.) 'That reputation's wrecked. His reputation with kids as this...hard-knock you don't mess with is wrecked too. Without a reputation to hide his secret behind, Neal Brose is...totally...completely...'

Say it, nudged Unborn Twin, I dare you to.

'...buggered, miss. Screwed and buggered.'

That appalled silence was my handiwork. Words made it. Just words.

Miss Lippetts loves her job, on good days.

My mind was scratching itself raw over how Mum and Dad'll react to what I did today, so I got the Christmas tree out of its cupboard as a distraction. The Quality Street tin of decorations too. December 20th's here and Mum and Dad've hardly mentioned Christmas. Mum's at the gallery seven days a week and Dad keeps going off for interviews that only lead to more interviews. I put the tree together, and strung its fairy lights. When I was a kid Dad'd buy real trees from Gilbert Swinyard's dad. Mum got this artificial one from Debenham's in Worcester two years ago. I whinged that it didn't smell of anything, but she pointed out I wasn't the one who had to hoover and unpick the needles from the carpet. Which I s'pose's fair enough. Most of the decorations are older than me. Even the tissue paper they're wrapped in's ancient. Frosted baubles Mum and Dad bought for their first (and last) Christmas alone together, without Julia or me. A tin choirboy hitting a high note, his mouth a perfect o. A wooden family of jolly snowmen. (Everything wasn't made of plastic in those days.) The fattest Father Christmas in Lapland. Precious Angel, from Mum's mum's mum. Precious Angel's made of blown glass she was a gift to my great-grandmother from a one-eyed Hungarian prince, so the story goes, at a ball, in Vienna, just before the First World War.

Step on her, said Unborn Twin. She'd crunch like a Crunchie.

No bloody way, I told Unborn Twin.

The phone rang.

'Hello?'

Clunks and grundlings. 'Jace? Julia. Long time no speak.'

'You sound like you're in a blizzard.'

'Call me back. I'm out of coins.'

I dialled the number. The line was better.

'Cheers. No blizzards yet, but it's freezing up here. Is Mum there?'

'No. She's still at the gallery.'

'Oh...'

Joy Division throbbed in the background.

'What is it?'

'Absolutely nothing.'

'Absolutely nothing' is always something. 'What, Julia?'

'Nah...nothing. When I got back to halls this morning, there was a message from Mum, that's all. Did she phone me yesterday evening?'

'Could've done. What was the message?'