The first probe to take up-close pictures of Pluto finds that the surface is surprisingly smooth with only a consistent series of strange dots to break it up. It's much smaller size than previously expected also meant that there was likely a tenth celestial body in the solar system throwing off Neptune and Uranus' orbits. People waited for the probe to return to Earth to take more accurate readings from it instead of choppy transmissions, but the probe disappeared. Over the years, as public interest in space travel grew after the discovery of primitive life on Mars, scientists began planning a manned trip to Pluto.

Three men were chosen, among them the narrator Robert. They discover upon landing that the dots are structures of some kind. With closer inspection, they appeared to be some kind of half-built tents. The planet was covered in dust, which made no sense as Pluto was too small to have an atmosphere which would keep anything down. They try drilling through the surface with a hand drill, but it is too hard. After analyzing the fragments that come up, they discover that it is made of steel, a non-natural metal. Pluto is manmade. The only solution that they can come up with is that it was built by something outside the solar system millions of years ago, to account for all of the dust.

With nothing else to do, the trio sweep the dust off the planet, searching for anything on the surface. They find three holes drilled in the shape of a triangle, and puzzle over what they could be for. Further dusting reveals a hairline fracture in the shape of a circle, meaning the holes were likely part of a lock and this is the door. With a yank, however, the door opens without needing to be unlocked and they discover a set of large scrolls. The scrolls contain detailed descriptions and specifications for building planets, in particular the planets of the solar system. There was even a planned one between Mars and Jupiter where there is now the asteroid belt. Pluto is nothing more than a tool shed with old schema at the edge of a mostly-failed solar system.