Fans of Alternity

McGonagall admitted to Arthur that the LP would be watching out for any insider who tried to steal the Stone.

I'm not sure I ever saw this exchange. It would fill a big gap in my thinking about events. I had a conversation with angstalaska where this may have been a root of my confusion. I didn't realize we had a clear sense of who knows the Stone is in the castle. If it is there as a result of the LP's actions, that's a big deal. (But why would he not keep it with him at the Palace and get to work on gaining immortality through its power? Why would Voldemort bother to warehouse it at Hogwarts. I get that Hogwarts is "safe," but safer than the place He Himself lives??)