Oh wow, the sex in this story was seriously white hot. Just. *starts a round of applause*
Loved the way Draco's terrible ability to lie or obfuscate was dealt with to humorous and poignant affect here. Harry's openness was so spot on, and the way it impacted Draco made for a wonderful story.
Great little moments with McGonagall -- her characterization of Hogwarts and inadvertent helping them to the eventual solution of their problem was nicely played out.
I really liked the discussions and arguments about magical theory and house-affiliation, the way they wove in and out of the characters' getting to know one another and becoming something substantial to each other. The story succeeded so well in exploring two people who were afraid of nothingness (Harry so keenly fearing not being able to help anyone, Draco just sort of disappearing as he hid from the world and took no course with his life) discovering the vitality and reality of their connection to one another. Lovely!