Excerpt from The Curious Incident of the Dog in the Night-Time by Mark Haddon, plus links to reviews, author biography & more

The rule for working out prime numbers is really simple, but no one has ever worked out a simple formula for telling you whether a very big number is a prime number or what the next one will be. If a number is really, really big, it can take a computer years to work out whether it is a prime number.

Prime numbers are useful for writing codes and in America they are classed as Military Material and if you find one over 100 digits long you have to tell the CIA and they buy it off you for $10,000. But it would not be a very good way of making a living.

Prime numbers are what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them.

23

When I got to the police station they made me take the laces out of my shoes and empty my pockets at the front desk in case I had anything in them that I could use to kill myself or escape or attack a policeman with.

The sergeant behind the desk had very hairy hands and he had bitten his nails so much that they had bled.

This is what I had in my pockets:

1. A Swiss Army Knife with 13 attachments including a wire-stripper and a saw and a toothpick and tweezers.
2. A piece of string.
3. A piece of a wooden puzzle which looked like this
4. 3 pellets of rat food for Toby, my rat.
5. £1.47 (this was made up of a £1 coin, a 20p coin, two 10p coins, a 5p coin and a 2p coin)
6. A red paperclip
7. A key for the front door.

I was also wearing my watch and they wanted me to leave this at the desk as well but I said that I needed to keep my watch on because I needed to know exactly what time it was. And when they tried to take it off me I screamed, so they let me keep it on.

They asked me if I had any family. I said I did. They asked me who my family was. I said it was Father, but Mother was dead. And I said it was also Uncle Terry but he was in Sunderland and he was Father's brother, and it was my grandparents, too, but three of them were dead and Grandma Burton was in a home because she had senile dementia and thought that I was someone on television.

Then they asked me for Father's phone number.

I told them that he had two numbers, one for at home and one which was a mobile phone and I said both of them.

It was nice in the police cell. It was almost a perfect cube, 2 metres long by 2 metres wide by 2 metres high. It contained approximately 8 cubic metres of air. It had a small window with bars and, on the opposite side, a metal door with a long, thin hatch near the floor for sliding trays of food into the cell and a sliding hatch higher up so that policemen could look in and check that prisoners hadn't escaped or committed suicide. There was also a padded bench.

I wondered how I would escape if I was in a story. It would be difficult because the only things I had were my clothes and my shoes which had no laces in them.

I decided that my best plan would be to wait for a really sunny day and then use my glasses to focus the sunlight on a piece of my clothing and start a fire. I would then make my escape when they saw the smoke and took me out of the cell. And if they didn't notice I would be able to wee on the clothes and put them out.

I wondered whether Mrs Shears had told the police that I had killed Wellington and whether, when the police found out that she had lied, she would go to prison. Because telling lies about people is called Slander.

29

I find people confusing.

Excerpted from The Curious Incident of the Dog in the Night-Time by Mark Haddon. Copyright © 2003 by Mark Haddon. Excerpted by permission of Doubleday, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.