The Big Read: A murder is announced

1. Some years ago at the Victoria Falls Hotel I met an elderly lady. She sat on a sun lounger on the green lawn with a tartan blanket on her lap, the smoke from the falls rising like bushfire in the distance, reading an Agatha Christie novel. "Oh, that's a good one," I said.

'They're all good," she replied. "I read them all years ago, when I was still in school."

I told her that I had too, except for The Man in the Brown Suit, which is set partially in the Victoria Falls Hotel but is one of her earlier, non-whodunnit novels. It's seldom in print and I'd never managed to track it down. She reached in her bag and retrieved an old paperback copy and gave it to me and I said I couldn't take it but she tutted and said it would lighten her luggage. She told me she had been waiting 60 years for her memory to fail sufficiently so that she could reread all the Agatha Christies and not know who the murderer was until the last page. "What a joy to live long enough to have such a pleasure twice," she said.

She was on a tour of the world, visiting all the places she'd been to as a child, travelling with her mother and her long-dead sister and her diplomat father, but everywhere she went she just found a good spot and settled down to read. She was worried, she said, that she might have waited too long, and that she wouldn't finish in time. And then I moved away to let her read in peace.

2. The first Agatha Christie novel I read was Cat Among the Pigeons, when I was probably 13. As I read it I drew up a list of suspects and annotated clues beside their names and made a diagram with arrows or dotted lines to indicate the strength of my suspicion. I stayed up late into the night, fighting the urge to flip to the final pages.

Hercule Poirot was my favourite of her detectives, the fussy Belgian gent with the luxurious moustaches and patent leather shoes and egg-shaped head. At some stage I conceived the ambition to write Hercule Poirot novels. On Saturday evenings in my teens when my classmates were out learning how to be social creatures and functioning human beings, I was at the desk in my room, making flow charts for a murder, trying to devise red herrings and elegant clues and diabolical solutions. In one of them, Poirot happens to visit Durban, and finds himself in a high school where a sarcastic, faintly brutal maths teacher named Mr Hawkey has been murdered and the problem is there are too many suspects with a motive. Write what you know, they say.

Trying to plot an Agatha Christie book taught me, aged 14, how little I knew, how much craft she had, and how much genius. Is it difficult to clothe such intricate machinery, such precise hand-tooled clockwork in such warmth and elegance and character and playful humour, to conceal the mechanics beneath human flesh? It is more than difficult, it is miraculous.

3. This weekend is the Franschhoek Literary Festival, when a cast of old suspects and new characters will converge on a small town to flit and flirt and talk about books and prepare small jewelled daggers to slip between each other's ribs, or vials of a powder savouring of bitter almonds with which to lace each other's wine glasses. It would be a grand setting for a murder mystery, but oh, how intricate the plotting. In a place where everyone is always watching everyone else, all the time, how would you fake an alibi?

On Sunday morning I'll be talking with the English writer Sophie Hannah in one of the venues, just her and me and an audience. It will be strange to be face to face with the person doing the job I dreamed of when I was a boy, but abandoned because I knew I didn't know how. Sophie Hannah writes the ongoing Hercule Poirot novels, a fact that fills me with admiration, and envy, and perhaps a little indignation. Give me back my dream job, Sophie Hannah, I think I can do it now.

Say, if something were to happen to Sophie Hannah, like for instance an unfortunate demise, perhaps live on stage in front of an audience, with no one obvious to blame, I'll bet that job would become vacant, wouldn't it? I think it should go to someone with the cunning to conceive such a plan, and the daring to pull it off in front of 200 wide-eyed witnesses. Yes, yes, I think it should. I'll see you on Sunday at 11.30, Sophie Hannah. It'll be fun.