The long finger held a wing.

A pterosaur's wing. A real structure, spectacular enough without adding anything to it.

Pterosaurs weren't dinosaurs. That mattered. The notebook was leading me across categories, not through a tidy family tree.

I drew the membrane. Then the whole animal. Then, on a separate sheet, I changed the head and added a dragon's body.

That was how easy it was. A real piece of anatomy became part of an impossible creature in a few pencil strokes.

Had I invented it? Of course I had made the drawing.

But why had I known which strokes to make before I made them?

The notebook offered no answer. Just another margin mark: the edge of the wing flattened into a long line.

I held the page sideways.

It looked like a horizon.

Then I saw what lay under it. Four pale shapes, arranged around a dark body. Flippers.

Water, not sky.

The notebook's next sentence was unusually clear.

Do not confuse a familiar story with a surviving animal.

That, at least, was good advice. A lake-monster shape in my imagination wasn't evidence for a creature living in a lake.

I wrote Plesiosaurus at the top of the next page.

Someone had already drawn its reflection.

The reflection had a door in it.