I cannot help but feel that there are multiple keys, and possibly multiple keystones.
Q has made numerous references keys and keystones with some room for misinterpretation in some of them.
Certainly the USA is a keystone of the LIGHT, so is the NSA, US MILINT etc.
There are darker keys and keystones.
Blunt and direct - a key in stone.
All roads lead to [R].
Would really appreciate a bit more clarification from Q on this.
Most likely never going to reply to this with a tripcode though.