The drawing was mine. The shadow wasn't.

I had put the Tyrannosaurus skeleton beside my notebook and started filling in what the bones couldn't show. Skin. Colour. The weight of the animal in the space around it.

On the next page I tried feathers. An enormous, bad-tempered bird. It made me smile. That was the point: take the same frame and see what another possibility does to it.

Then I turned back.

The first drawing now had two shadows. One belonged to the dinosaur. The other spread sideways, as though something behind its shoulders had opened.

Wings.

I checked the lamp. Moved the model. Looked for a reflection. There was nothing wrong with the room. The extra shadow was pencil, on paper.

There is no evidence that T. rex had wings. I wrote that across the bottom. Whatever this notebook was doing, it wasn't allowed to turn a drawing into a scientific discovery.

Below my sentence, in smaller handwriting, were six words.

You are drawing the nearest version.

I didn't remember writing them.

I counted the marks along the edge of the strange shadow. Six. Small loops, like feathers seen end-on.

Beside the notebook sat another skeleton. Velociraptor. I had not drawn it yet.

Its name was already written on the next page.

Underneath: Start with the arm.