Somewhere in the southwestern United States, among the cacti, low shrubs, and shifting desert sands, there is a plain white box. In poor light and from a great distance, the box might look something like a phone booth. However, from close up, it is clear that the box is like nothing else on Earth. While it is only slightly narrower than one might expect, it is much taller, stretching to almost twice the height of a human being to accommodate the creatures who designed it. It is also completely blank and devoid of surface features.
For most of the year, the box has no identifiable doors or windows. However, on December 22nd of every year, between the hours of four and seven in the evening, the eastern wall of the box opens up, and you can step inside. Why the box only allows entry at this particular time is unknown, but the handful of people who have stepped through the doorway and returned tell fascinating stories about what the box contains.
The general tone of the stories suggests that the box is a pathway into a complicated transportation network, something like the subway line of the cosmos. It was apparently built by someone who visited Earth in the very distant past, likely long before the emergence of humanity. No one knows how to select the destination where they will find themselves when they open the door again, and some have reported going through as many as two hundred stops before finding themselves back on Earth.
The box was built out of sterner stuff than its designers. Most travelers report that the box opens into enormous and glorious ruins, built in orbit around at least a dozen worlds. Some of these are still entirely functional space stations, running on autopilot for eons after the deaths of the creatures who built them. Some are little better than derelict hulks, their internal atmospheres reeking of decay and humidity, and their lights long since turned off to save what little power is left. It seems entirely possible that some intrepid travelers have stumbled upon ruins completely dead, and found themselves choking to death in vacuum.
However, even barring this substantial risk, there are still dangers to traveling among the dilapidated structures built by a long vanished empire. Although no one has reported coming into contact with anything hostile or indeed even alive within any of the artificial worlds to which the box may lead, some have claimed to hear unusual sounds echoing in the far distance on some of the darkened stations. One young man who traveled to a particularly large structure in orbit around a gas giant reported seeing movement in the blackness at the end of a hallway, something which sent him running back to the safety of the box, and eventually back to the Earth.
It must be remembered that the civilization which built the box fell. To what, no one knows. Perhaps it was simple bad luck, perhaps a galactic pandemic. Or, perhaps like the Roman Empire, the builders of the box were wiped out by the barbarians who managed to push through the gate. Perhaps those barbarians, like the ones who eliminated Rome, have partitioned the spoils among themselves.
Credited to C.S.B.