Sudden brain blast over morning coffee:
John Gaius, necrolord whatever, cringiest man alive, refuses to let the earth die. And not just in the literal sense of locking the earth’s soul in a barbie on ice, in subtler ways too.
The most obvious is the memes, John constantly references memes that are dated even to us, but are in universe from a culture that died ten thousand years ago!
Slightly more subtle is the years. Why does everyone in the Houses measure in earth years? It’s been ten THOUSAND years since anyone lived on the earth! But John keeps them as a unit of measurement.
Even more subtle is the language. In sci-fi and fantasy we’re all used to the idea of the translation for the reader, people don’t speak english in lord of the rings, or dune, but the dialogue is in english for us, the readers. Not in The Locked Tomb. In this series, they ARE speaking english. Modern, bog standard english, to the point where two people born thousands of years apart speak similar enough dialects that one can pose as the other (dulcie/cytheria).
Now, this could possibly fall under that standard sci-fi trope, EXCEPT!!!! In Nona The Ninth, we see the non-house humans! And they speak dozens of languages, like you’d expect after TEN THOUSAND YEARS of linguistic drift!
John is trying SO HARD to keep the earth alive that he’s forced a language to stagnate for, say it with me now, Ten Thousand Years, to the point where even completely new things with no equivalent in our world don’t even have new words, just repurposed old ones (flimsy, sonic).
John Gaius, the first necromancer, could resurrect the planet itself, and millions of people, but he couldn’t resurrect the culture. So, John, cryogenics researcher, tried to put the culture on ice, to keep it as close to the one he remembers as possible. And he still failed.