HarryRocks101
Day is going normally in Selac, one of the main core homeworlds of the Federaton of the Mantle. The planet, as always, is bustling with activity, its livelyhood portrayed in the masses of vehicles, ships that ascend and descend within the planetoid's orbit, and many more ships supplying to the industry and the inhabitants.
However, this was no common day, for today was to happen an event that happens only once in centuries. Today was the day that all of the orbits of the orbiting celestial bodies of the system would line up in a singular sequence. To say that thousands of cameras were aimed at the sequence was an understatement, as an event of probabilities like this is almost unspoken of, though more of a conceptual than a material event, it somewhat signified the opening of their Federation to the cosmos and the galaxy, turning a new page in their history, and this event to signify it.
That is, until something weird happened. At about 10 seconds before the moment of apex, the zenith, all of their equipment stopped working simultaneously. All of the groupthink of these people attracted another event of cosmic proportions, as their equipment came back just in time to capture it emerging from the umbra of its eclipse, a thirteenth "planet" within the system.
It seems to move extremely fast for the distace to its center star. There seem to be no traces of how it came to be in its place, but its orbit seems to be such that it does not affect the orbit of the other objects within the system. For some reason, everyone seems to have a shared feeling that, once it completes a full orbit around the star, it won't be there anymore. Cameras and scanning equipment pick up faint signals of it, ruling out the possibility of a collective dellusion, it seems to be real, and the first anomaly the Federation has come to face, at least of this kind.
"It" is what seems to be a space-station almost the size of the core world. Seemingly composed of some kind of black and grey plating in its entirety, there are no visible weaponry on the outside, though its exact topology and interior composition are a mistery due to a particular cloud of "golden hazyness" that surrounds it, impeding any valuable insight without...
An expedition to its interior. Done before the time runs out. Objects seem to be able to enter its area, but only one at a time, else they simply phase through the whole structure as if it wasn't there, as demonstrated by a few stray asteroids. What is the decision that the Federation will take to face this unexpected occurance? One can only wonder what they can discover from this misterious structure.