Morgana, Moon And Magazine

"The Problem of Pain," introducing the planet that will be Avalon, mentions that the planet has a single small moon. That moon will be called Morgana. A periodical will be named after the moon. Judith Dalmady/Lundgren will write short stories to be published in that periodical. Centuries later, Hloch will collect three of those stories in The Earth Book of Stormgate. Also in Hloch's time, the Terran Navy will bombard the moon, Morgana, so that mountains crumble and afterwards the moon shines less brightly than before. See here.

Reading the references to a small moon in "The Problem of Pain," we do not suspect that so much history still lies ahead of us - unless, of course, staying with the original publication order, we read The People Of The Wind before The Earth Of Stormgate. In that case, we already know of Avalon and its later history and are interested to learn how it was first explored by Ythrians employing some human beings.