McGonagall's Ancestral Aegis

Fireside Ghost Story with a twist! This was written years ago for a fest, the recipient being tjs whatnot. I changed the title from "Mission Possible" to "McGonagall's Ancestral Aegis" as I feel it fits the theme of the fic a little more. Snape and McGonagall try to drink one another under the table. A very inebriated Snape has an otherworldly visitor. Minerva helps him dissemble