User blog comment:Arbington/ME3 Theories/@comment-2116719-20100630063534

There is one thing you people left out, the Keepers, think about ever since the arrival of the asari to the Citadel the Keepers were there but they barely talked and are keeping the station running, it was even said that there are places in the Citadel that have not been discovered by anyone but the Keepers, and the Keepers might have been there even before the protheans arrival, add to it that they know how to keep the Citadel running, so they might have the technology to fight the reaper invasion and that they might help Shepard by telling him/her how to do it.