Omg, I don't know, but you certainly convinced me we should go balls to the wall with this. Both "the Outsiders" and the "Guilt that haunts me" ideas I found appealing.

With the outsiders I think its worth while considering how technology is analogous to magic. I'd like them to be somewhat balanced with each other though somehow. Perhaps it's technology the spacefarers no longer really fully understand. Perhaps that is what lead them to loose their place and come seeking shelter on this world?

I like the "Guilt that haunts" me idea just as baldfaced as it is, but another option is it could also be a mechanism to include or to interface one of the Outsiders idea into the world. Such as deed opening and closing the rift that is intersecting the two worlds.