He stands at the front of the class, his thick, calloused hands gripping two beakers. His lab coat has stains and burn marks.

"And now, students," he says, his voice cracking as he holds the two beakers just moments apart. "Make sure you have your safety goggles on..."

He doesn't look up, because if he did, he'd see every last student in the room ducking behind their desks.

Some even hold up books... just in case.

"And now, with the combination of pure tyrannium and a dash of slothite, we find..."

The two beakers tilt -

The chemicals fall -

Just a single drop -

As the chemicals mixed, the orchestra practicing on the other side of the school heard the explosion!

Mr. Leer teaches the Potion Brewing Basics class - one of the most feared classes in the entire school. Not because of the grades, but because nobody's really sure if Mr. Leer knows what he's doing!

On the other hand, Mr. Leer could be the best kind of mad genius. He seems to stumble across chemical combinations that other professors can only scratch their heads at.

Meanwhile, his students have to sit in class - sometimes hiding behind their desks - observe, take notes... and keep their fingers crossed!