He recalled a stellar eclipse he had witnessed on a long-forgotten world, whose single moon was of perfect size and distance to blot out the light of the system’s primary. The result hadn’t been total darkness but illumination of a different sort, singular and diffuse, that had confused the birds and had permitted the stars to be seen in what would have been broad daylight. Even totally blocked, the primary had shone from behind the satellite’s disk, and when the moon moved on there had been a moment of light almost too intense to bear.

