I said, “I wanted to come and tell you that I didn’t kill Wellington. And also I want to find out who killed him.”

Some of her tea spilled onto the carpet.

I said, “Do you know who killed Wellington?”

She didn’t answer my question. She just said, “Goodbye, Christopher,” and closed the door.

Then I decided to do some detective work.

I could see that she was watching me and waiting for me to leave because I could see her standing in her hall on the other side of the frosted glass in her front door. So I walked down the path and out of the garden. Then I turned round and saw that she wasn’t standing in her hall any longer. I made sure that there was no one watching and climbed over the wall and walked down the side of the house into her back garden to the shed where she kept all her gardening tools.

The shed was locked with a padlock and I couldn’t go inside so I walked round to the window in the side. Then I had some good luck. When I looked through the window I could see a fork that looked exactly the same as the fork that had been sticking out of Wellington. It was lying on the bench by the window and it had been cleaned because there was no blood on the spikes. I could see some other tools as well, a spade and a rake and one of those long clippers people use for cutting branches which are too high to reach. And they all had the same green plastic handles like the fork. This meant that the fork belonged to Mrs. Shears. Either that or it was a Red Herring, which is a clue which makes you come to a wrong conclusion or something which looks like a clue but isn’t.

I wondered if Mrs. Shears had killed Wellington herself. But if she had killed Wellington herself, why had she come out of the house shouting, “What in fuck’s name have you done to my dog?”

I thought that Mrs. Shears probably didn’t kill Wellington. But whoever had killed him had probably killed him with Mrs. Shears’s fork. And the shed was locked. This meant that it was someone who had the key to Mrs. Shears’s shed, or that she had left it unlocked, or that she had left her fork lying around in the garden.