Snape, who had been very gradually leaning forwards, sat back in his seat again, apparently satisfied that he had the answer he had been looking for. He nodded slowly, "I see," he turned his gaze to the tower window, and for a long moment simply stared out at the sky beyond. As someone who Harry had never once detected even a hint of self-doubt in, in that moment he could practically hear the internal argument that Snape was having with himself. He could certainly see it in the clenching and relaxing of Snape’s jaw and the tensing of the muscles in his neck. Finally, his black eyes were back on Harry, "Potter... Black and Lupin...,"  