The tube belonged to Parasaurolophus.

I followed the crest through the drawings. Hollow passages. Air. A structure researchers could model to explore the sounds it might have helped produce.

An instrument without its music.

That was what got me. We could recover the shape. We could build a model. But we couldn't stand beside the living animal and listen.

I imagined a low call in the dark. Then a bright one. Then something that sounded less like an animal than a gate being opened a long way off.

The third belonged in a story. I labelled it as such.

Nothing happened.

For the first time, the notebook stayed completely ordinary. I made tea. Answered a message. Came back and found the page exactly as I had left it.

I should have been relieved.

Instead, I noticed that my three imagined sounds had made three different landscapes. Same skeleton. Different worlds.

I drew the last landscape again. A passage through trees. Something waiting beyond it.

At the bottom, almost without thinking, I made a fan of short lines. Not sound this time. Light.

The fan was the fourth mark in the notebook's margin.

I checked the earlier pages. Shadow. Points. Curve. Fan.

Each drawing had left something behind.

On the facing page was a horned head, washed in colour.

I knew which creature it was. What I couldn't explain was why the paint was still wet.