On Siobhan’s advice, Christopher includes descriptions of things in his book. He goes out into the garden and sees the clouds, which he describes as looking like fish scales and sand dunes. He spots a particularly large cloud moving slowly on the horizon that looks like an alien spaceship and thinks that it could easily be one. Aliens, if they exist, would probably be very different from humans. They could be made of air, like clouds, or just about anything else.