This is another twisty tale from Michael Coney, who also wrote the classic little novel THE JAWS THAT BITE, THE CLAWS THAT CATCH, also THE CELESTIAL STEAM LOCOMOTIVE. It would help if you had read the first volume, but it isn't totally necessary.
From back cover: Millenia ago Starquin visited the Solar System. Because he is huge - some say bigger than the Solar System itself - he could not set foot on Earth personally. Yet events here were beginning to interest him, and he wanted to observe more closely. So he sent down extensions of himself, creatures fashioned after Earth's dominant life-form. In one of Earth's languages they became known as Dedos, or Fingers of Starquin. Disguised, they mingled with Mankind.
We know this now, here at the end of Earth's time. The information is all held in Earth's great computer, the Rainbow. The Rainbow will endure so long as Earth exists, watching, listening, recording and thinking. I am an extension of the Rainbow, just as the Dedos are extensions of Starquin. My name is Alan-Blue-Cloud.