But he knew it was something big, but at so great a height from the earth as to look like a fly.

And then he caught sight of a second black speck, then another and another, until he could make out a dozen or twenty, or more, all moving in wide circles at that vast height.
Martin thought they must be the black people of the sky; he wondered why they were black and not white, like white birds, or blue, and of other brilliant colours like the people of the Mirage.
Now it was impossible for Martin to lie like that, following those small black spots on the hot blue sky as they wheeled round and round continuously, without giving his eyes a little rest by shutting them at intervals.

By-and-by he kept them shut a little too long; he fell asleep, and when he woke he didn't wake fully in a moment; he remained lying motionless just as before, with eyes still closed, but the lids just raised enough to enable him to see about him.

And the sight that met his eyes was very curious.

He was no longer alone in that solitary place.