Waste not, Want not
Mana from Heaven it was, almost literally.
We woke one day to a strange rain, flaming meteorites the size of cars streaking down to blast craters out of fields, streets, and houses. Thousands of them fell over the course of a month, and thousands died from the impacts.
About four weeks after it had started, it was over and we began to investigate the craters. And in those craters, we found canisters containing wonders: Technological artifacts of purpose and complexity just barely outside our comprehension. Carcasses of animals whose body plans and genetics were like nothing we’d ever seen.
In the next year, as we just started to scratch the surface of these mysteries, our world changed forever. Diseases were cured, aging was stopped, and our minds expanded ferociously. We moved out toward the stars, yet never did discover the nature of our astonishing windfall.
The ancient garbage scow lumbered away from the tiny blue-green planet. Its holds were emptied, ready for another load from home.