Shared Universes

Poul Anderson had a knack of writing stories set inside other authors' fictional universes. In "The Last Word," Harry Turtledove does this with SM Stirling's Draka and their Janissaries. Turtledove knows how these guys think and speak. A sixth-generation Zulu Janissary spoke:

"...in accents that might almost have belonged to a von Shrakenberg." (Drakas!, pp. 253-254)

We know what that means if we are familiar with the series.

Turtledove also understands Anson MacDonald:

"'Better for Americans to die as free men than to live as slaves.'" (p. 257)

"'We've got no magic way to throw the Snakes back across the Atlantic. We can't very well start a new religion and go crusading against them.'" (ibid.)

In Heinlein's The Day After Tomorrow, Americans do overthrow invaders by starting a new religion. And, I have just remembered, references to chess are common to The Day After Tomorrow and "The Last Word." It will take me a long time to penetrate such a rich text.