That was really lovely. I like the dreamlike atmosphere, not sure if it's really happening or not. And I love the idea that Luna is not quite human. :) And this --

"I couldn't live with myself in the light of day."
"Severus," she said, "you will never see the light of another day."

-- gave me the shivers. And also put in place any doubts I might have had about making their bond sexual. :) Oh, Luna!