My take on Keystone: It is the stone that joins the two sides of an arch. Legislative Branch is one side, Judicial Branch is the other side, Executive Branch (Office of President of US) is the 'Keystone. Neither of the other two branches can really function without the Keystone in place. AmIRightQ??
Shep is most likely a former kidnapped kid reprogrammed by the cabal. trust nothing he says. Same with several other leftist Journos.