What I Did In My Christmas Holidays - By Sally Sparrow. Written by Steven Moffat. Illustrated by Martin Geraghty.
I gasped in even more amazement. There was another Sally Sparrow and obviously she was taking the photograph. And probably she was a bit deaf, and you had to talk to her with paper signs, because hearing aids hadn't been invented yet.
And then I looked at the next photograph. And that's when everything changed. Suddenly it was like the school bell was ringing in my ears and I could feel my heart thudding in my chest so hard you could probably have seen the buttons bouncing on my pyjamas.
There was the man again, at the back of the photograph, holding up another piece of paper. And this one said 'Look under the wallpaper again.'
As I reached for the wallpaper again my hand was shaking away like when you try to do your homework on the school bus. The next bit of writing was much longer and this is what it said.
'This isn't a dream, and by the way you should never try to do your homework on the school bus. I'm going to prove this is real. Think of a number, any number at all, and then get dressed, find a torch, and see what's carved in the bark of the furthest tree in the garden.'
When people think of a number, they always think of ten, or seven or something. They never think of a really big, stupid one. So I did, I thought of a big, stupid one. Then I halved it. Then I added my age. Then I took away Tim's age. Then I added four, just because I felt like it. And then a few minutes later, I was standing in the garden, shivering, staring at the furthest tree.
And there it was, carved like it had been there forever. No one ever thinks of the number 73. Except me. And the man who had carved the furthest tree in my Aunt's garden twenty years ago.