Keystone = the layout of Arlington National Cemetery.
That's where the bodies are, in a sacred US cemetery, Arlington.
BOLT HOLE = Obutma's hideout located under Arlington.
POTUS's comment about 'expanding' the cemetery is actually a way to expose BOLT HOLE to the public when ever they start to expand it.
Planefags photos of aircraft making the 'keystone' pattern.
POTUS standing next to infinity's logo a shout for us to pay attention to that area.