Snape and Dumbledore enact an old tradition in the castle, hoping to gain a much-needed edge. More-or-less AU starting at book 6. Rated for language and smut.

In her sixth year, Dumbledore makes Hermione a key figure in a plan to help Harry defeat Voldemort. (It's difficult to summarize this without spoilers— HG/SS; there's a Time Turner involved but probably not how you expect; the story really gets started in Chapter Three.)