Big Universe

Publication dates of Technic History instalments featuring Ythrians:

"Wings of Victory" (April, 1972)

"The Problem of Pain" (February, 1973)

"Lodestar" (1973)

"Wingless" (July, 1973)

"Rescue on Avalon" (1973)

The People of The Wind (February-April, 1973)

The Day Of Their Return (1973)

Thus, a single burst of creativity. These instalments span the period from the first Grand Survey to the later Terran Empire. In "Wingless," David Falkayn has led the human-Ythrian colonization of Avalon. In The People Of The Wind, his descendant, Tabitha Falkayn, is brought up by Ythrians on Avalon.

In Mirkheim, Falkayn remembers the splendour of a flying Ythrian. Later, he says that he would be content to settle on Earth but his wife, Coya, disagrees so he considers his birth planet, Hermes, but then adds:

"'Maybe. We'll see. It's a big universe.'" (XIX, p. 262)

Mirkheim was published in 1977. Thus:

the Ythrian burst of creativity was by then four years in the past;

Anderson knew that the Falkayns would settle on Avalon although they did not yet know that;

anyone reading the Technic History as it was published would have understood the significance of the Falkayn's dialogue.

A future history series is cemented together by inserting later-written instalments between earlier-written ones.