Hermione receives a very strange note. Minerva asks her to help remove Snape's Dark Mark. Snape writes poetry.

My chambers are dark, lit only by the glow of the midnight moon. The castle creaks with rawness of stone and antiquity of magic, filled with the power welling up from beneath the mountain and the fire of intention fuelled by our four vibrant streams of magic, combined. It is nearly impossible to recognise this expanse of land from just six months ago: pristine grasses as far as the eye could see, cresting on a tidal wave of green, the shadow of grey stone a skeleton underneath. A spider's web holding together an enterprise that, tonight, feels like folly. I had expected to feel exultant.

Did you ever wonder what happens behind the scenes at Hogwarts?

WIP, SSHG, DH-compatible. "Dear Hermione..." Twenty years after the Battle of Hogwarts, she thought she'd received all the letters there were, and despaired. But there was still one letter to come...

Hermione Granger was a witch. By the time she was done, the whole damned pureblood world was going to know it.
HG/SS. Spoiler HBP

All that intelligence just has to be genetic.