Not enormous, but the longest thing we have ever had to edit, Legacy Earth introduces a earth eons hence, reconstructed by super humans who didn’t quite get it right,  Here is the introductinon, the brief prologue the begins part one, The Quickening:

The Quickening


It was a scene of unimaginable darkness.  Had we been there, you and I, we would, from our vantage point, have been immediately struck by the absence of light and the complete silence, the very lifelessness of it all.

Oh, if we had a light, we would have seen trees laden with leaves and fields of grass, but while at first glance it would have seemed to indicate life, we would have quickly realized that it was an illusion. The trees, the grass, the entire world was lifeless and while filled with things that we would recognize as elements of life, the utter stillness, the absolute silence and the total darkness would very quickly inform our senses that but for ourselves there was no living thing.

The vista for as far as one could tell was dark and silent and lifeless.  Since no one was there in the darkness complete, there was no vista.

Then from our imagined viewpoint on an airless hill, intense patches of purplish, pink light that grew and spread rapidly to cover our entire view would suddenly dazzle us.

Had we been in a spaceship not too far away we would have seen the light envelop the orb on which in our imagination, we had been standing.  Looking outward into the surrounding space, we would’ve observed pockets of the same phenomena occurring for far as the naked eye could see.

Back on our imaginary viewpoint, we would be overwhelmed by a change as inconceivable as the lifeless stillness we had encountered just moments before. In a split second the purplish pink light would vanish, and we would be surrounded by the subtle sound of animals, the thrumming of insects and the humming ticklish breeze ruffling the grass and leaves. Then in the east, a bright shiny orb would appear a rising above a distant and verdant horizon. At that very moment, we would discover ourselves to be in a warm summer morning surrounded by life.

While we were not really there to experience it, that is the very thing that happened.

It happened because the time of mankind was now passing. The last remnants of humanity, to us, god-like creatures, were on the verge of transmutation into pan-dimensional beings, in which the last remnants of humanity would be shed. Before leaving their humanity behind, they had decided that they would leave a legacy to their human origin.  They would revitalize the long dead sector of the Milky Way Galaxy that held within its burnt out and scattered particles, their original home, the tiny planet of earth and the cold and lifeless ash that was once Sol one, a G-type star that had once warmed the tiny Solar System from whence they had sprung.

They had decided that their legacy would be built around the period when early humans had first begun to move beyond the limits of their tiny world and stood on the threshold of space. God-like, but not gods, they searched everywhere to gather the elements to provide authenticity to their re-creation.  Working with what they could find, or they could understand, vast as that was, these majestic beings revitalized the stars and planets around their early home, and reinstituted life as it would have been around the 21st century.  Their creation, like the environments they sought to recreate, like all creation, was imperfect. They rebuilt the 21st century with broad strokes that spread over 500 or more years.  With the eons that had passed, it was good enough, and as they left this phase of existence behind, they were confident that their precestors would as they had, make the necessary corrections.