Black Cat (слэш)

As of late, The Boy Who Lived has taken up a new activity, one which no one else knows about. He has recently become an unauthorized animagus, taking the form of a black cat with glowing green eyes. Unable to sleep at night, he wonders the castle instead, and in his new form he's able to remain unseen by Filch or any noble prefects looking for a student out past curfew.
It's on the third night of this charade that he dares to venture down to the dungeons, which is where he discovers his most hated professor, the potions master of the school, Professor Snape, has a horrible sleep schedule just like he.
But, something about seeing the man lent over a bubbling cauldron, illuminated by the soft glow of the moon and his long strands of black hair obscuring his face from view, intrigues Harry enough to venture into the classroom he usually fears, and to pad up to the professor who he fears even more.