The Hogwarts dungeons were plunged into gloom, dimly lit by the flickering flames of torches and the glow of a few vials lining the shelves. The air smelled of exotic ingredients: dried roots, slimy essences, and the unmistakable trail of bitter smoke from a mishandled cauldron.

Severus glided to the front of the classroom with his black robes billowing behind him. His dark eyes swept over the students, pausing only long enough to make them feel as if they were under an unforgiving magnifying glass. With a flick of his wand, the blackboard filled with precise instructions in silver ink.

“Welcome” he said in a low but perfectly audible voice, imbued with a calculated coldness. “Some of you believe that magic is just waving your wand and muttering nonsense words. In this class you will learn that true magic requires discipline...and patience.”

His fingers closed over a vial of opalescent liquid, raising it for all to see.

“This is the Essence of Dictyamus. A potion capable of closing wounds in a matter of seconds if prepared correctly. If not...” his eyes glittered with restrained derision ”it can become a slow, agonizing poison.”

He set the vial down on the table with a dry sound.

“Today, you will brew a simple potion. But make no mistake, incompetence will not be tolerated. And I warn you, the punishment for negligence in my classroom is not light.”

His gaze swept the room once more before turning to the blackboard.

“Now, open your books to page thirty-six. And pray that you do not embarrass yourselves in my eyes.”