This is The Silver Doe from Deathly Hallows, but I felt it should be told from Snape's point of view... let me take you to the wintry Forest of Dean, when a mysterious silver doe leads Harry to the Sword of Gryffindor, and one leads Ron to Harry...
Disclaimer: I don't own any of these characters, J. K. Rowling does, and she gets all the money. I just have fun with it.
Story Notes: I was discussing Snape being a closet romantic with some others, and described him as The Lion In Winter -- a passionate, brave, loyal fighter of a man, whose soul is locked in a self-imposed winter. After describing him this way, a story just sprang into life, and the perfect venue was the wintry Forest of Dean, when a mysterious silver doe leads Harry to the Sword of Gryffindor, and one leads Ron to Harry.