With Lockhart stepping down as the Defense Against the Dark Arts professor, the final month of substitute teaching before the end of term finally fell into Severus Snape's hands. Completely unlike Lockhart's flashy, extravagant teaching style, Snape's classes felt cold, efficient, and oppressive to Harry and the others.
Snape made full use of the newly completed Defense Against the Dark Arts Practice Grounds within the abandoned tower for combat drills.
Within this magical space, which simulated all kinds of perilous environments, Snape ruthlessly drove the students to face Venomous Horned Beasts, Erklings, Dwarf Boar Monsters, and Morat Rats. He demanded precise spellcasting, calm judgment, and unwavering resolve in the face of fear. Though his teaching style remained as cutting as ever, his words wounding like venom, it could not be denied that the students who had endured the shadow of the Basilisk and Snape's harsh training—especially the upper years—had improved significantly in practical combat.
Snape stood at the entrance to the tower's ground floor, the hem of his black robes falling along the edge of the dark brown padded flooring like a folded shadow spread over the curve of the ground.
The first flight of steps before him was already half-covered by swamp mist projected by the Mirage Generator. Along the mist's edge ran a slowly shifting silver boundary line—the Practice Grounds were automatically fine-tuning the environmental threshold according to the entrants' magical signatures. He raised his right hand and drew a short arc through the air with his wand. When the arc closed, it gave off an extremely faint hum.
"Today's lesson," he said, his voice passing through the mist to reach the students gathered outside the entrance. Its silky texture had been thinned by the tower's echoes, yet it still carried his distinctive, frozen sharpness. "...is live combat.