Anomaly Ost-Theta-Maxima
Orbiting a red dwarf at the farthest edge of the Oestalan Sector, a small asteroid has been cored out, with a mile-wide hole bored through and filled with an ancient portal device. Dead and inert, it is surrounded by equally decayed defensive weaponry and a host of ancient derelict vessels whose age defies explanation and whose origin is totally unknown.
An Ark Mechanicus has journeyed out to investigate the colossal ruins, in the hope that it is something akin to the Jericho Gate, though activating the gate has proven impossible thus far.
What no one knows is whether or not the gate builders left the fleet to guard their back door, to hold their entry point, or if the fleet is even of the same species as the gate makers.
Rumors and fears have begun to circulate that the dead fleet is actually guarding against something better left sealed away in the darkness beyond the galaxy.
However, tantalizingly, the gate itself has a few eroded markings that are very similar to Dark Age of Technology script. One of them is reminiscent of the symbol for an STC. The prospect of recovering a complete STC has made the magi uncaring of the danger, and they will unlock the gate if it takes them ten thousand years.