His gaze swept over Harry, Ron, and Hermione. It was unlike any time before—still scrutinizing, still carrying its habitual air of assessment, but the pure malice had been replaced by something more complicated. Harry could not name it, but he could sense the subtle change within it.
"Remember the fear, chaos, and... instinct for survival you felt here." Severus Snape spoke the word "survival" so softly that it nearly dissolved into the air. "Defense Against the Dark Arts has never been something you can master through memorization and empty boasting. The... barely passable abilities you displayed today may perhaps help you survive one second longer when true darkness descends."
He turned and headed for the entrance to the tower. His black robes billowed behind him, raising an arc of wind that brushed the base of the control console at the edge of the grounds, lifting one corner of the data log board atop it. He did not turn back to straighten it.
When the door closed behind him, it made a low, dull sound, like the latch of a box being shut.
The tower fell quiet. Only the fading hum of the Illusion Generator shutting down remained. Harry stood in the middle of the grounds, slipped his wand into his sleeve, and raised a hand to touch the scar on his forehead. That old mark had twitched briefly during the final round of the confrontation.
"Let's go," Ron's voice came from the side, carrying a little more steadiness than usual—perhaps more than he himself realized. "He said 'barely passable,' but I bounced that Erkling's Mimicry Charm back at it three times."
"Three and a half times," Hermione corrected, with something almost cheerful in her tone that she tried, but did not quite manage, to conceal. "The first time, you only