Wow, that really packed quite a punch. Mystery, suspense, unexpected discoveries, denial, passion, and finally revelation. :) Very nicely done and the concept of magic changing to help him, and then to bring them together was intriguing. I especially liked the concept of an unexpected bond.
Specifically, I loved how his taciturn nature despite his handicap becomes accepted by the shop girl, I liked his nosy Muggle friend, and how Snape had trained himself to learn the villagers by their sounds and actions. The image of Severus shaking with the effort to control himself in Hermione's presence after they kiss, as well as his repeating "Mine" over and over as he finally makes love to her, are very compelling, indeed. :) Thank you so much for a lovely and captivating fic!