Professor McGonagall stared down at the pieces of parchment on her desk, her fixed gaze attempting to focus on the essays in front of her. Normally, grading homework was something that she was able to systematically, without thought, but tonight it seemed that she could make no headway regardless of how hard she tried. Mentally reprimanding herself for not getting more sleep in recent nights, she struggled on.

Human Transfiguration can be used to great effect in many situations, particularly…

Yes, thought McGonagall. It was a decent start. The daylight was starting to fade noticeably now, her window only providing enough light to barely make out the scratchy quill-marks on the parchment.

…particularly when disguising oneself, for obvious reasons. Altering of distinctive features…

She was barely taking in what she was reading. Lifting her gaze wearily, McGonagall's eyes alighted on her own emerald-green traveling cloak that was hanging neatly from a stand in the corner. The first year Potter boy had distinctive emerald-green eyes…

It seemed like so many years ago that she had waited for Albus on the brick wall in Little Whinging. Harry Potter couldn't know, then, what he would grow up to be, doomed to spend years being raised by relatives who had no love for him. That fateful night returned to Professor McGonagall's memory quite clearly despite the intervening decade; a small bundle had been laid on the doorstep, not knowing that his parents were taken away from him already, Lily and James Potter gone forever.

A mere week before Voldemort had murdered them, Minerva herself had spoken with them at the headquarters of the Order of the Phoenix. In fact, she realized with a pang, she must have been one of the last to do so; the safety guaranteed them by the Fidelius Charm would have required them to remain indoors as much as possible. Like any new parents, they could scarcely breathe for bragging about their new son; though Minerva could not remember any of the exact conversation (it had seemed so trivial at the time), she recalled that the Potters could not have been happier. James had been the proudest man in the world, telling everyone who would listen about the boy's future Quidditch career. Lily had been a little quieter, but Minerva remembered the look on her face, how she had positively glowed with happiness when looking at her son…

A knock at the door shook Professor McGonagall out of her reverie. Hastily wiping her eyes, she made her voice as crisp as ever when she spoke. "Come in."

The door opened and the sallow frame of Severus Snape entered the room. "Professor McGonagall. Is this a bad time?"

"Not at all, Severus. I'm just grading papers."

"The headmaster has asked me to speak to you."

"Ah." McGonagall looked at him closely. "Yes. As you know, all of the core teachers are going to be doing their part in fortifying the third-floor corridor. I am going to be arranging the levels of security and so I was going to ask you whether you had finished your plan for the Potions bit."

She looked at him expectantly.

"Yes, I have," he said. "I intend to prepare something of a logic puzzle, using several different potions…" As Snape explained the details of his plan, McGonagall felt herself losing focus again. He had the blueprints of his piece sorted out; that was all that mattered.

When he finished explaining, McGonagall said, "That's all I needed. Thank you."

Snape nodded. "Certainly. I will have it prepared as soon as the potions finish maturing." He turned towards the door, but McGonagall spoke again.

"Oh, and Severus, before you go – Albus asked me to, but as it's closer to your office, would you bring the Mirror of Erised to its new home when you get a chance?"

Without turning back around, he paused. Did she imagine the sound of a sharp intake of breath following her words? "I will do it," he said at length.

"Thank you, Severus."

McGonagall's gaze was now troubled as she watched the door shut behind him. She felt she shouldn't have made her last request as soon as the words had left her mouth. All thought of grading essays forgotten, she realized what she had asked of him with a sudden sensation of guilt: in moving the Mirror, Severus would almost certainly have to behold its terrible power.

She was not the only one to suffer from that tragic night ten years ago.

Professor McGonagall felt a single tear fall upon her cheek.