The flight into space that made Pilot-Capt. Dan Barstow famous. He was one of the very first astronauts to leave the earth -- and what he found surprised even him. "Another world." Small and too dark to see from the earth -- but large enough to capture his spacecraft. Large enough to get trapped on it.
Take a board with 64 squares on it. Put a grain of wheat on the first square--two on the second--four on the third. Keep doubling in this manner and you will find there isn't enough wheat in the world to fill the sixty-fourth square. It can be the same with compound interest.
It has been 60 years since the great Red Death wiped out mankind, and the handful of survivors from all walks of life have established their own civilization and their own hierarchy in a savage world. Art, science, and all learning has been lost, and the young descendants of the healthy know nothing of the world that was-nothing but myths and make-believe. The old man is the only one who can convey the wonders of that bygone age, and the horrors of the plague that brought about its end.
After some sudden and unspecified catastrophe has depopulated England, the countryside reverts to nature, and the few survivors to a quasi-medieval way of life. The first part, The Relapse into Barbarism, is the account by some later historian of the fall of civilisation and its consequences, with a loving description of nature reclaiming England. The second part, Wild England, is an adventure set many years later in the wild landscape and society.