My favourite theory was that McGonnagal was a spy for Voldemort. I totally bought it. Read the beginning of the Philosopher's Stone with the idea that she's on Voldie's side and it totally adds up. (And how did she know Dumbledore was going to be there?! So mysterious!) I was relieved to be wrong, though.
A;ALKSDJF A;KDSJFA HAHAHAHAHA OH WOW. I mean how dare you she is my queen, but that’s pretty funny. HOW DID SHE KNOW. oh because she’s BAD ASS