Nineteen.

That was the average age of the wizards and witches killed in the battle of Hogwarts. Minerva McGonagall had worked it out one evening when sleep eluded her, after checking that all the previous heads of the school were fast asleep in their photo frames, her eyes lingering over Snape's and Dumbledore's, she left the office and navigated her way out to the memorial, the disillusionment charm she placed upon herself holding fast as she passed various ghosts with no disturbance. The witch never forgot a face, that had always been something she'd prided herself on, so as she scanned countless names on the list, it was far from difficult to calculate their ages and, by doing so, the average. Minerva didn't know why she did it. She stood in the pouring rain before this mighty marble plaque, swallowing a rising lump in her throat as she contemplated the absurd fact that she had outlived so many of her own students. She knew that was not how life should work. There were more wrinkles on her face than there had been years of these people's lives and it wasn't right. She knew it wasn't right and it hurt. After all, your teachers are supposed to be the all-knowing people who lead you in the right direction and then, after you achieve your potential, you come back and visit them, and they look at you with misty eyes and a proud smile, telling that they knew you would do well.

And yet, McGonagall hadn't been able to save them. Not during the year when those damn Carrows had been destroying the students, not during the holidays when she received owls from countless children saying that their parents had disappeared and they didn't know what to do, not during the battle when despite her insistence that all underage students left, kids like Colin Creevey came back and ended up as another name on the marble plaque. And as a teacher Minerva had never felt more useless and pathetic than when she was having tea with Hermione Granger and saw her sleeve slip up to reveal the word "mudblood" carved into her skin. When the younger witch saw where her eyes fell, colour flooded her cheeks and she hastened to pull her sleeve down, fighting the tears that welled in her eyes. Minerva McGonagall had called Hermione the brightest witch of her age and encouraged her and believe in her but none of that could rescue her when she was being tortured by a crazed Bellatrix and she felt so damn guilty that she had to excuse herself to the bathroom where she retched and shook at the look of pain in her young ingénue's eyes. And when she came back and Hermione was crying softly, the young witch practically fell into the open arms offered by her teacher, whispering that she had hoped that by some miracle "Professor McGonagall might have come to rescue me" and Minerva felt like she'd been stabbed in the gut, although her only response at the time was to pull the young woman closer and attempt to soothe her. Or when Ginny came back for her final year and she walked past the spot where Fred died for the first time and fell into Hermione's arms, while other students stared openly and the newly appointed headmistress silently cast a disillusionment charm over the pair so that they could grieve in peace. And Professor McGonagall had remained so strong in the public eye, never allowing herself to show weakness to the young people who so desperately craved the consistency she provided; never in her whole life had she seen such relief on students faces than when it was announced that the headmistress would continue to take her transfiguration classes on top of her headship. She never even allowed herself to falter in her office, ever conscious of her predecessors watching her from their picture frames. So now, as she sat by the plaque in the pouring rain, her disillusionment charm totally faded, she began to cry. Tears working their way down her face, she began to sob.

Minerva's whole body contracted as she wept. She wept for the families who lost their children, parents, siblings and god she knew there was so many of them. She wept for the parts of the castle still being repaired, a constant reminder of all the destruction caused. She wept for the Slytherins, still outcast by their peers, mostly because everybody assumed that these were the next generation death eaters even though they weren't and these poor children had done nothing to provoke this prejudice. She wept for the golden trio whom she knew were all haunted by night mares of the horrors they had seen, she knew this from the almost regular owls she would receive in the early hours of the morning from any one of the three, to which she would have to find a comforting answer in order to soothe them. But most of all, Minerva McGonagall wept for the fact that the average age of those killed in the battle was 19, most of all, she wept because if anybody had to die, it should have been her; instead of Remus, or Tonks, Fred, Colin. All these people who hadn't even lived half of the years she had, seen half the things she had, done half the things she had. It was all wrong and as the headmistress slipped into a feverish, terror filled sleep, the number 19 burned itself into every part of her brain.

It was Hagrid who found McGonagall in the early hours of the morning as she lay curled up beneath the names of the fallen and he soon put the pieces together. Rubeus Hagrid, despite not being the most intellectual of men, was highly observant and had known that it would only be a matter of time before Minerva finally broke. He lifted her off the ground, grimacing sadly at the older woman, noting the sheen of sweat across her forehead which surely spoke of a fever, as well as her drenched clothes which confirmed the suspicion that she had been there since the night before. She stirred in his arms as he began the walk up to the hospital wing and he paused as her face contorted and tears began to slip down her cheeks, while she seemed to be trying to make herself smaller, clutching her knees close to her chest and shaking.

"Nineteen"

Hagrid frowned, he had no idea what that meant but it was clearly distressing the headmistress and a quick glance at the clock told him that the students would be out of bed soon and to see Professor McGonagall like this would destroy the morale slowly built up after the battle and, Merlin, if Hermione or Ginny saw her then he dreaded to think what their reaction would be. Taking care not to hurt the older woman, he tightened his grip slightly and broke into a jog, ignoring the questions fired at him from various paintings and simply insisting that

"This 'ere situation stays quiet, yeh 'ear me?"

When he finally made it up to the hospital wing, Madam Pomfrey was just dismissing a pair of girls as he hurtled in. Naturally, Hagrid's appearance was impossible to miss and all three women turned to face him. Both of the younger pair went pale as they recognised the figure currently unconscious in the gamekeeper's arms and Hagrid silently cursed as he saw the two faces he had least wanted to see. Hermione clutched Ginny's arm, tears welling in her eyes; it was no secret that McGonagall and her star pupil had a very close relationship and so it was unsurprising when Hermione's legs gave way and she fell into the hastily conjured armchair, summoned by Ginny who, although she was shaking, managed to keep her balance. It was, however, Madame Pomfrey's reaction that was the most severe as she emitted an ear piercing shriek and raced to her friend, helping Hagrid to put her into a vacant bed before conjuring up some screens faster than you can say "pumpkin juice". The hospital wing was silent apart from the occasional clang from within the screens and the steady sobs from the conjured armchair. It was utterly bizarre that any part of Hogwarts should be silent as it was usually buzzing with magic and life, so the absence of any sound made everybody feel uneasy. Ginny traced circles on Hermione's back, trying to soothe her as she sobbed, while Hagrid simply stood, cursing himself for not waking earlier.

"I assure you Madam Pomfrey, I shall be fine"

Minerva's Scottish burr came eventually, weaker than before but clearly audible in comparison to Madam Pomfrey's quiet tone,

"No I do not need to go to St Mungos and why are you whispering?"

More urgent mumbling,

"There are students outside? Which- oh..."

Minerva cursed herself for not being more wary, she had inevitably terrified the two girls, both of whom had already suffered enough and certainly did not need to imagine their teacher in such a state,

"Miss Granger, Miss Weasley, come in,"

The two girls exchanged glances before cautiously opening the curtain, terrified at what they might see.

It was the heavy sighs of relief that told Minerva just how much the pair had been worrying and she was struck with another pang of guilt as she knew that she was the cause of their concern.

"I'm going to be fine," the promise was hollow, everybody knew that, but the headmistress felt that it should be spoken anyway,

"It's nothing serious, I was outside for a late night stroll and tripped, nothing mo-"

"Bullshit," the words came fiercely from the red headed student and McGonagall raised an eyebrow

"Excuse me Miss Weasley?"

Ginny seemed to struggle with herself for a moment before the words came tumbling out,

"Have you cried yet?"

Whatever the older witch had been expecting, it certainly wasn't that and so she took her time in the reply as, she didn't want to lie to the girls, but also didn't want them to see what she herself perceived as weakness. The three sat in silence for a short while until the headmistress felt a presence in the back of her mind and smiled knowingly to herself,

"Miss Granger if you could kindly refrain from using leglimency on me, that would be much appreciated,"

The brunette flushed a dull pink and apologised quietly, her eyes now fixed on her own trembling hands.

"What I am about to tell you is something highly personal and I would hope that both of you would keep whatever is said right now to yourselves, is that acceptable? Of course, if either of you feel the need to talk to somebody about this, understand that my office door is always open, I will send you any password changes by house elf is that clear?"

A unanimous nod was Minerva's response and now, as her nerves rose in her throat, she found herself wishing they hadn't agreed. However, she was a griffindor and now came a time when she would have to summon up that legendary bravery.

"Nineteen,"

She whispered and, for Hermione at least, all the pieces slotted into place and her heart went out to the older witch. Ginny, however, was baffled,

"I don't underst-"

"The average age of the witches and wizards killed in the battle of Hogwarts,"

Hermione cut off Ginny and the realisation dawned on her freckled face as McGonagall attempted a wobbly smile; still trying to remain strong under the gazes of her students. Ginny turned to Hermione, her bottom lip trembling as their eyes met and the elder of the two nodded weakly,

"When did you figure this out Miss Granger?"

"19 days after,"

The headmistress nodded, feeling the tears brimming in her eyes but swallowing the ever-rising lump in her throat,

"Do you know how old I am?"

Hermione shook her head while Ginny's cheeks flamed to match her hair,

"I will take your reaction, Miss Weasley, to mean that you do, in fact, know my age; most likely courtesy of one of your older brothers,"

The youngest witch nodded minutely, whispering the figure so quietly than nobody was able to hear her, Minerva raised her eyebrows amusedly at the girl's shyness,

"Miss Weasley if you do not speak up I shall be forced to use a sonorous charm upon you and although I am comfortable with the pair of you knowing my age, I'm not sure I want the entire school knowing the extent of my years,"

Ginny giggled shyly before meeting her headmistress' twinkling eyes,

"You're seventy-three I believe?"

Minerva looked vaguely impressed by her knowledge,

"Very good Ginny, now, Miss Granger? I believe you are the strongest mathematician amongst us?"

Hermione flushed again, this time with pleasure at the praise rather than embarrassment,

"Do you know how many times nineteen goes into seventy-three?"

"3.8,"

"Very good Hermione,"

Now came the hard bit; the teacher bit her lip and took a deep breath as she prepared to relay the fact that had been haunting her,

"I have taken up almost four times the amount of life that most of the people in that battle had, I outlived 39 of my own students, that's not how it's supposed to work? It's not supposed to be the teacher attending her students funeral, it's not suppo-"

The words caught in Minerva's throat and her momentary pause was the final straw which sent Hermione hurtling into her teacher as she threw her arms around the woman she had looked up to since she was eleven years old. Ginny watched them for a short while before silently slipping away, knowing that this was a moment she ought not to be a part of; besides, she needed to send an owl to Ron and Harry to inform them of the recent occurrences, although naturally leaving out the parts that she had been sworn to keep private.

The two witches remaining in the hospital wing wept together for a considerable time before Hermione felt that she was strong enough to pull away. She looked into the slightly reddened eyes of her teacher and smiled weakly,

"In nineteen years time, there'll be kids from our era coming to this school,"

McGonagall nodded, tears slipping silently down her wrinkled cheeks,

"These kids will know all about those who fell, and they'll tell their kids and they'll tell their kids and they will never be forgotten... But professor, it's okay to hurt over this, you know that so many of us still struggle to sleep, I know it was you who cast the disillusionment charm when Ginny broke down. But if you spend the rest of your life feeling guilty that you lived longer than those people, then you're doing them an injustice and, well, the Professor McGonagall I remember would never allow that to happen,"

The professor in question sat with the tears still rolling down her cheeks, having long since abandoned concealing them,

"Thank you Hermione," she whispered, her voice still slightly hoarse,

"No biggie," the younger witch shrugged and smiled at her teacher,

"I ought to go find Ginny, will you be doing the assembly or do you want me to talk to Professor Flitwick?"

The older witch shook her head, already beginning to climb to her feet,

"No, that won't be necessary, I'll take the assembly, although if you could inform Hagrid that he is invited to join me in my office after dinner tonight, that would be most appreciated,"

Hermione grinned, beginning to make her way out of the screens,

"Will do professor,"

"Oh and Hermione?"

"Yes?"

"Call me Minerva,"

19 Years Later

Professor McGonagall met the new influx of first years on the steps as she had done every year for nearly 70 years and quickly noticed the familiar faces in the group, Albus Potter, Rose Weasley, Scorpius Malfoy... Yes, Hermione had indeed been right that the next generation would be arriving in nineteen years. Minerva's welcome had become less and less formal since the Battle of Hogwarts so by now, when an especially small first year threw his arms around her waist she barely flinched, smiling down at him and ruffling his hair,

"Hello Mr Longbottom,"

The little boy grinned up at the woman before blushing a little and returning to the group, all of whom were looking at the headmistress with a collective awe,

"Now, first years, it has become the tradition that before I escort you to the hall where you will be sorted into your houses, I take you outside to see an integral part of our history, now come along,"

She led them across the grounds, narrating as she went various points of interest such as Hagrid's hut and the Forbidden Forest, until they reached the great marble plaque with the names of the fallen inscribed onto it,

"Nineteen years ago, the battle of Hogwarts took place. These names are all those who fell, from both sides. So many young witches and wizards with boundless potential were killed in this battle- by showing you this memorial, we keep their memory alive, we keep their legacy,"

"Uncle Fred!"

The small red-headed girl whom Minerva had correctly identified as Hermione's daughter came hurtling forward as she spotted the name. Rose Weasley turned to face the other first years, bursting with pride despite the tears brimming in her eyes,

"That's my uncle!" She stated proudly, crossing her arms in such a Hermione-ish way that McGonagall could have sworn that it was Hermione back at Hogwarts again.

Nineteen years had passed.

All was well.