As usual for me, one of the most immediate reactions is to drop it into the Fading Suns setting, one of my favorite kitchen sink settings.
Basic Premise: Aliens Among Us
In the setting of Fading Suns, humanity has encountered at least one enigmatic and powerful alien race: The Vau.
It's been hinted that they are carefully watching humans, for some reason unfathomable to the citizens of the Known Worlds. Perhaps, in addition to all the reasons cited in the books, it's because they know that we've been gifted or touched by a power that they have also encountered -- and fear.
That power is evident in the many artifacts that come from the Zones. It's rumored that the ability to activate the Jumpgates comes from technology that originated in the Zones.
Other alien races -- especially the Ur-Obun and Ur-Ukar -- are kept in the dark about the very existence of the Zones, and only a select few of the powerful factions on Terra know about the long-sequestered Zones on Earth.
On the Front Lines: Scravers & CharioteersThe Killroy sub-faction of the Charioteers therefore serves a dual purpose. Not only do they protect the value of the jumpgates for their guild; they also work to safeguard people from the potential consequences of unrestrained use of Zone technology.
Unknown Agendas: The Annunaki
Of course, one of the continuing mysteries of the setting centers around the old 'gods', the Annunaki, who are assumed to have built the jumpgates and were responsible for the Ur-Obun and Ur-Ukar races.
If they are indeed tied to the Zones, one can see the power of the lowest levels of their abilities -- creating artifacts that defy the conservation of energy, warping gravitic fields, and the strange corruptions of the strands of human fate that can result in the delayed (or passed on) fatality of many a human line.