"Look at this, Professor Holmes."
Snape seemed very displeased with Douglas's silence.
He picked up a black prism ground from crystal.
"The Dark Spectrum Mirror."
Snape introduced it.
"It can analyze the stability of a potion's magical fluctuations."
"Muggles call it... quality control?"
He placed a drop of potion on the lens.
A steady green wave of light appeared in the mirror.
"Perfect stability."
Snape announced arrogantly.
Then he deliberately picked up a failed sample beside it.
He dripped it onto the lens.
The light waves instantly became chaotic.
A blurry skull appeared on the mirror's surface.
"This is the work of an imbecile."
Snape's gaze swept over the class.
"Abnormal fluctuations mean toxicity."
The atmosphere in the classroom instantly turned ice-cold.
Douglas had to admit it.
Though Snape had a vile personality.
He was a true genius at Potions.
No, not just Potions. Snape had always been very good at innovation.
He had taken the modern concepts Douglas provided.
And integrated them perfectly into his own system of magic.
And stamped them deeply with the mark of Severus Snape.
A dark, exacting mark, yet precise to an outrageous degree.
Snape walked over to Fred and George's stone chamber.
The twins were working together to process a bundle of valerian root.
"Weasley."
Snape's voice was like a snake's hiss.
"Your cutting angle is off by three degrees."
George's hand shook, and he nearly dropped his silver knife.
"Professor, we..."
"Do you think you're making those boring toys of yours?"
Snape interrupted him.
"If this potion were meant for a patient, your three-degree deviation would be enough to stop his heart."
He reached out a finger and tapped the edge of the obsidian workbench.
A concealed magical device activated.
A small mirror rose from beneath the worktop.
What appeared in the