Being a potion master had its perks at times. But this wasn't one of them, having to go out in the middle of the night to be able to cut a few roots that would be available only at that time and in the bushes at the edge of the Forbidden Forest was usually not fun. It had been a successful expedition though, so he was satisfied, even enough to circle the lake to come back to school, making his walk longer, just to watch the sky, stroll and enjoy for once his being alone.
He didn't notice the light coming from the edge of the lake, too busy in his own doings, he really didn't think there was anyone around until he was hit by something. Right on his head. And he fell like a pear: knocked out.