There was something about the look on Marlene's face that was making Benedict think that maybe, just maybe, he was starting to crack through that teenaged armour that the students all seemed to have - especially, as he knew from experience, the Slytherins. He was actually letting himself start to feel hopeful and like this hadn't been a waste of his time or McKinnon's. And then there was a flash of lightning outside, bright enough to force him to close his eyes for a moment, and all of the lights went out.
His classroom was actually very dark without any lights, Benedict idly observed in the two or three seconds it took his mind to fully grasp what had just happened. Somehow, he didn't think it would have been quite this dark.
He heard noises from where McKinnon had just been, no doubt her leaping out of her seat. He slowly stood up himself, looking around to see if there was anything still visible in the sudden plunge of darkness, listening to McKinnon try and fail to perform Lumos. She was nothing if not an able student and Benedict had no doubt that if she couldn't get the charm to work, then it wasn't because she was doing it wrong, but he pulled his own wand out all the same. He attempted to non-verbally cast the spell himself without success. "Huh," he muttered.
Unable to see McKinnon, but hearing slight movements to indicate that she was still there, he carefully made his way to his desk. He felt his way down to the bottom drawer, where he kept his stash of very expensive, special-occasion-only-and-no-Bertram-you-coming-to-visit-does-not-count Cuban cigars hidden. He fumbled around inside the drawer for just a second before triumphantly locating a box of wooden matches. Just as he was moving to strike the first one, he heard McKinnon's whimper and frowned. He struck the match and went back to her in the dim light. "You alright, McKinnon?" he asked, pocketing the box of matches and putting a hopefully calming hand on her shoulder. "It's okay. Who's here? What do you mean?"