I've got ideas for other alternative timelines Albus and Scorpius might have visited, but this is a (soppy, gratuitous) standalone fic for now.
There's only once during that terrible time that Severus Snape's resolve to maintain his Death Eater mask faltered.
It's just after the Battle of Hogwarts of course, and Snape's insides are already reeling, and surely there is no more hope, for Potter was strung up on the wall like a morbid, lifeless puppet, and Death Eaters danced and shouted beneath him finally assured of their final victory. No, it was not then that his resolve faltered, though he had tried to assist Potter in any way he could during that battle without blowing his cover, only to fail miserably. Wave after wave of crushing, nauseating regret threatened to consume him; he had failed Lily's son, he had failed. He should have died protecting the boy, and instead he was faced with the prospect of a future where he could only see bleak darkness; for regardless of the handful of Order of the Phoenix members causing stabs of panic, what were they without a fulfilled prophecy?
No, it was not then; and in the twenty-four years that passed since, not once did his outer mask falter or change, or was anything revealed that might cause suspicion. His demeanour was a blank mask. There was only once, a chilly afternoon two months after the end of the final battle, where that mask came anywhere close to breaking.
Minerva, of course, had stayed to fight to the end; reckless, fool-hardy Gryffindor that she was, she was at the forefront of all the action, and had refused to flee with the others when it was clear all was lost. But they didn't kill her immediately; no, that would have been too kind for the Dark Lord, and a fate far too kind for someone who had been his sworn nemesis for near fifty years. He'd captured her and careened her somewhere into the darkness, and Snape didn't think he'd had a heart left to care; but it had hammered in his chest as he watched them drag her away, a bleeding and broken mess who now faced a fate far worse than death.
He had nearly, very nearly started after her; but no, again, it had not been in that moment that he had broken. Instead he stared after her with his blank eyes, as if he saw nothing at all.
He had known that she would not be killed immediately, but held somewhere out of reach, to face torture and rape. He had tried with some subtlety to understand where she and the other captives from the battle were held, but their location was shrouded in secrecy, and so much transpired in those following two months there was too much to do besides.
For one thing, Dolores Umbridge seemed to hold some lingering ambition to reclaim her title as Hogwarts Headmistress. The numbing, autopilot stupor in which Severus found himself snapped when he discovered the news, and he intended to fight her viciously, for the only thing that could be worse than a future lead by Voldemort was one where the students found themselves ruled by the power-mad, delirious Umbridge. It was a lofty notion and the new school year was not due to start for some time, but she had raised it at the last meeting of the Board of Governors, with a sympathetic, simpering look in Snape's direction, stating that he was a perfectly adequate Headmaster but clearly had other priorities to tend to.
In this, the toad was right. Oh, he'd downed quite a few Death Eaters during that battle; but it seemed he'd also done enough damage for the other side to talk his way out of it, putting it down to what he told the Dark Lord 'must have been the Imperius Curse'. A few Cruciatuses had put him right back in the inner circle, for after all, he was still the hero that had killed Dumbledore, and so there he was right back at Voldemort's teat. There were all sorts of complicated potions that needed to be brewed, all sorts of raids against traitors that only Snape could be entrusted with, which Snape did with customary aloofness.
The moment came two months later, when Snape found out exactly what else Umbridge had been busy with, and Snape had been tasked with what he was told was a particularly meddlesome task. He was lead into the bowels of the Ministry, past dungeon after dungeon, the air cold and damp with the centuries' old history of dysentery and death. He had a terrible sense of foreboding as he walked with Rowle and Umbridge at his heels; a terrible sense that he knew what he would find when he reached the last cell. When they walked through the metal door he was not wrong.
He did not recognise her, at first. There were five other occupants in the room, and there was an overwhelming stench of defecation and illness as they lie prone in their own filth, moaning into the darkness. Clearly this cell was reserved for what was considered the worst of the blood traitors. Each occupant was covered in tattered rags and skeletal from starvation, so that they looked near identical. But his eyes snapped violently between them, because he knew deep down that if he were to find her anywhere, this would be it; and finally his eyes came to her, hanging from the wall by magical chains, her head limp against her shoulder. All he could see was her long black hair straggled around her sunken cheekbones, so that she already looked dead; but she was unmistakeable, he was certain it was her.
Severus could only stare transfixed at her, his heart pounding in his chest just like when he'd seen her dragged away, the first time he had felt anything for the last two months. As if from far away, he heard Umbridge's voice floating to him at his side.
"Obviously it's awful that we have to be here at all, amongst this filth; but it was the Dark Lord's specific wish that Ollivander be restored to health, if possible. If we're to build a strong base of magically pure wizards and witches, they'll need the best wands available, and the only one who came close was Gregorovitch. And of course that's not an option now. Traitorous as Ollivander was in the final battle, we need him, and the Dark Lord thinks he has sufficiently learnt his lesson by now."
But it was clear Snape did not hear her, and Umbridge's eyes trailed to what he was watching so intently.
"Oh, I see you've recognised your 'old friend'," she said, with a simpering laugh that made Snape's blood boil. "Yes, she's been trussed up here like a turkey since the final battle. Haven't you, Minerva dear?"
Minerva said and did nothing, so Umbridge continued.
"She's had special treatment, for of course she's an old friend of mine, and of the Dark Lord's too I hear. You'll enjoy this Snape."
Umbridge marched over to where McGonagall hung against the wall and pulled apart the rags covering her arm, so that Snape could see the burns and open, festering wounds blistering up her arm and shoulders, and presumably beyond where the rags covered what was left of Minerva's dignity. It took all of Snape's self-control not to double over and vomit on the spot.
"I understand that Rowle and the boys have had some special punishments for her too - but I think it would be improper to speak about such matters," Umbridge added with a sniff, but the fact that she alluded to it at all confirmed all Snape needed to know about Umbridge's sense of propriety. The cogs in Snape's head whirred quickly, trying to see a way out for Minerva.
"Who will teach Transfiguration in her absence?" Snape said, his voice deliberate in its coolness, his eyes still on the burns across Minerva's body. At his voice, Snape could see McGonagall's head move a fraction of an inch upwards towards him, and his heart beat harder; but it seemed to go unnoticed by Umbridge or Rowle, who stood just outside of the dungeon waiting for them.
"I am told Lucius Malfoy is a decent transfigurationist," Umbridge stated with an air of indifference. "It's not like he's particularly busy with other business these days. You weren't seriously contemplating having her come back and teach at Hogwarts, were you?" she asked suddenly, though her large mouth stretched wide over her face in an incredulous smile, as if she were to burst into raucous laughter at the very notion. "Minerva? One of the very worst blood traitors? Who has opposed and defied us both at every step? Oh, even if you and I were to be lenient Severus..." And at this Umbridge ran a stubby finger across Minerva's scarred cheek, which more than anything he had seen this afternoon sent shivers down Snape's spine.
"The Dark Lord will never let her live. I understand she has only been allowed to live as long as she has for his own amusement... were you aware that he paid her a visit himself?" And Umbridge said this with equal parts amusement and envy in her voice. "No, I don't think she has long left, I'm afraid." Umbridge turned away from McGonagall, and there was a moment where McGonagall's unkempt hair shifted and Snape could finally see her eyes staring into his; exhausted and half-dead, but not hate-filled, not anguished, but so grateful to see some glimpse of him that he nearly crumpled on the spot.
"There is a restorative draught that I will be able to provide Ollivander," Snape said carelessly, tearing his eyes away from Minerva and looking supremely disinterested in everything happening around him. "It will take two days to complete in the dosage strength that he requires. He should probably be kept in a separate cell until then."
The plan had formed in Snape's head from the moment he walked in, but he had hesitated until he had seen Minerva's blue eyes watching him. He could not stop himself from speaking.
"I... am aware that this request may seem improper," he began slowly. "However, Minerva and I have… unfinished business. If this is the last opportunity that I'm to have to see her, then I would like to instil my own form of punishment on her, if I may."
Snape's face was so hard set and vicious that Umbridge simpered in her delight, not knowing that Snape's anger was directed squarely at her.
"I understand the sentiment better than anyone Severus. Of course, I can't give you a lot of time, with the wards shifting..."
"I only need half an hour," Snape replied, his eyes never leaving Minerva. "You can return then, Rowle. The draught will be with your team in two days."
Their retreating footsteps echoed around the corridor, and he waited stone still until he could no longer hear them; then he crashed in a heap against Minerva, supporting her weight so that she no longer hung by her wrists.
Did it matter that he give himself away here? That he tell her everything, that he was miserable, that he regretted every harsh word and action over the last year, over the last twenty years; he was certain that the others in the room were so half gone that they would pay them no mind anyway. Would Minerva want to hear what he had to say; would she even be able to understand him?
"Minerva," he breathed into her hair. He cast the spell that released her from her bonds, so that she sagged in a heap in his arms, and it frightened him when he held her, that she felt nothing more than a bag of bones. Umbridge was right; she didn't have a lot of time left.
Before he did anything else, he conjured a cup of water, gently holding her head up by the hair with one hand and holding the cup to her mouth with the other. Their faces were close so that he could see her more clearly now, and his stomach turned at the sight of her; her right cheek was swollen and broken, and deep cuts layered her face in intricate patterns, so that it was clear someone had spent an inordinate amount of time cutting into her skin for their sick pleasure. Her right eye, on closer inspection, seemed crusted with something; he was not sure she could see him through it. There were so many injuries that he could and couldn't see that he was desperate to heal her, but could not think of where to begin.
McGonagall was so sick that most of the water dribbled down her cracked lips and chin, but again she looked so eternally grateful that what remained of Severus's heart twisted in his chest.
"Oh Severus," she breathed, her voice not much more than a throaty crack. "The hell you must be in."
It was so Minerva that she had managed to put it together, again; but even moreso that she thought first of him, when she herself sat tortured and dying in a dark, pitiless cell. For a second it felt like old times, and he had to fight the urge to laugh, or to start sobbing against her.
"I can't say it seems like much of a walk in the park for you either. How did you figure it out?"
"You've obliviated me. My memories are missing. For a year I skip from approaching your office ready to confront you to having an angry, solo midnight Firewhiskey."
"I wouldn't have had to if you weren't such a meddlesome, overly heroic Gryffindor." She smiled at that, pressing her hand into his.
"Did they hurt you terribly?"
"I am alive. And still in the inner circle. So no, not terribly."
"And the others, Severus?" she breathed.
"They're out there. About twelve of the Order. I helped Arthur and George escape - I'm not sure how the others managed."
"Enough of them, then," she sighed with relief, her eyes closing and a trace of hope in her voice, and Snape had to marvel at how she could still hold any hope after all the time she had spent in here at the hands of the Dark Lord and his sadistic minions. But he felt it too; he felt it talking to her, felt it as he watched a face that was scarred and maimed, but still, miraculously, alive. There was still some glimmer of hope for them both.
"You need to transform," he said suddenly. "Do you have enough strength?"
Her eyes flashed open, then, as if seeing him for the first time; then her expression was one of such pity that it alarmed him.
"Oh Severus, no," she breathed.
"Then I can heal you; conjure you a restorative-"
"Severus - if they find me missing, with you the last person to see me alive - you'd be better off in here."
Snape blinked at her.
"You're suggesting as an alternative that I leave you here to die."
"You're too important to risk," she said simply. Her voice grew quiet. "And no, I'm not suggesting that."
He was too moved at her suggestion that he was too important, that he missed the meaning of what she was saying, and it took him a second or two before realization dawned, horrifying and stark. The hope he had felt extinguished, and he saw their reality for the first time; the darkness of a cell several storeys underground, with countless armed guards and no hope of disapparation. McGonagall had known it for two months, but still she had looked so relieved to see him, and now he was starting to understand why...
His face was frost as he looked at her.
"What are you suggesting."
"Severus..." With what energy she had left, she lifted her other hand so that it clasped his too, bony and spindly, two of the fingers looking badly broken. "I know what I'm going to ask you stretches the bounds of our friendship, particularly as the last time we spoke, if I recall correctly, I called you a coward amongst other things... but you showed mercy once, when Dumbledore stood dying on that tower-"
"No."
"-I ask you... please... to show that mercy again."
"No."
"There is no escape from here. If you leave me alive..." She faltered, here, for the first time since he'd entered that sad dungeon and saw her. "Well, I will spare you the details, but that anyone could consider this existence 'being alive' is laughable. Please Severus... the alternative is a fate I wouldn't wish even on Umbridge."
His teeth gnashed and he watched her with utter, open hatred now, pulsing and unadulterated, furious at her presumptions and her daring to even ask this of him. As if he hadn't sacrificed enough; as if he hadn't given enough of his soul to this hopeless, fruitless effort, and now she dared to sit in front of him, quietly asking him to murder her. Had she only been happy to see him because she thought he would be the one person capable of killing her out of this mess? Had she thought of him once besides, given him any sort of cursory thought outside of being some kind of morbid saviour? Did she think of what it would do to him to have to kill her... oh, he was so angry at her, so angry that tears sparked painfully at the edges of his eyes.
"No," he rasped.
"I need you, Severus," she whispered.
"That's not fair," he hissed.
"If I am subject to one more humiliating session with V-with that bastard," she spat. "Oh believe me, if I could have found a way to do it myself, I would have done so already."
"Minerva..." But even as he spoke he realized the futility of every argument he could put forward, and saw very clearly her point. If the situations were reversed, Minerva would have killed him, there was no doubt; and moreover, he would have wanted it to be her.
And yet, it had been different when it had been Dumbledore. He had been able to mechanically put that aside, to feel as if that murder was something done by someone else; looking into the face of his former colleague now, realization was slamming, choking, because he knew he would not be able to so easily compartmentalize this. He had existed alongside Minerva for twenty years, first as a student but later as equals; he felt like he knew her as well as anyone knew her, and she the same. Killing her would be like ripping away apart of himself. He would only admit it in his darkest moments alone, but he had missed her company terribly in that final year as Headmaster.
"I'm not sure if I can do it," he breathed, his long hair falling to hide his stricken face. He could feel her hands squeeze his.
"Think of it as a favour to an old friend," and he could hear the smile in her voice.
He looked up at her and he knew, like every stubborn argument they'd had in the last twenty years, that against his will he would ultimately acquiesce to her. They were running out of time; if ever there was a moment for truths this was it.
"I regret all the horrible things I said to you," he breathed.
"Even the part about Gryffindor dunderheads?" McGonagall replied lightly, but he could see the tears glittering in her eyes too.
"Especially the part about Gryffindor dunderheads. I..." But he could not finish the sentence. She squeezed his hands again.
"I know Severus. Me too."
Suddenly he was crushing her to him, all limpness and protruding bones, and he tried to imprint in his memory the warmth of her spindly body against his, and the feel of her face against the crook of his neck. They pulled apart and Severus held up her face with his left hand, for he knew that she could not hold it up with her own strength, so that he could look into her face one last time, and take with him into the uncertain future the memory of what it looked like to be cared for.
And that was the moment his resolve as a Death Eater spy broke, and he nearly gave himself away. Because how would he explain why McGonagall had been murdered? If he were smart, if he were in any way strategic about this he would have just banished her memories and walked away to leave her to her fate; he'd had his moment, he had looked into her face and gotten the closure he'd needed. He should have left her alone.
"You have always been a hero, Severus," she exhaled. "Never a coward."
Pleading blue eyes met black, and he could not resist doing anything she asked of him; and the room flashed with green.
By the time Rowle came back, Snape had re-composed himself as an obelisk of black nothingness, telling Rowle he couldn't stop himself from getting one over the foolish, stubborn Gryffindor one last time. Inside, he hoped wherever the foolish, stubborn Gryffindor was now, she was happy; and that Rowle would not notice his hands shaking as they left the dungeon.
The next time Snape felt a glimmer of hope was when Scorpius Malfoy appeared in his classroom twenty-four years later, spouting some nonsense about being from an alternative timeline.
By that point the black nothingness had continued for twenty-four long years, interspersed with half-hearted attempts at raids and the hopelessness of seeing the Order whittled down to two desperate felons. Night after night he subsisted in endless darkness; racking his brains for a plan that would not come, a peace that would not afford itself to him, a happy ending that would not exist.
So he thought he was going delirious with madness when he not only listened to the boy's tall story, but actually started to believe him.
He knew he must be dead in the alternate timeline, of course; no one spoke of the honour of speaking with someone, or looked in as much awe as Scorpius had, unless they'd never met. He rued over that part while Ron and Hermione bickered and bantered over the semantics of their plan, unable to look each other in the face, of course, having not ten minutes ago realized they'd put together enough brain cells between the two of them to get it together in another universe. Snape was mildly surprised to find he didn't mind too much that he had died a hero's death, and felt more surprise still that he was ready to die all over again in this universe, if it meant a future where the Dark Lord was defeated.
It was the fate of someone else he was preoccupied with, that he itched to ask Scorpius about but didn't dare for fear of revealing himself. For if there was an alternative universe where Potter lived... surely Minerva had lived as well.
He knew it was all over when Umbridge happened across them, and finally he could not pretend any longer. He'd sent patronus after patronus to protect the boy and to keep the dementors at bay, ostensibly his happy thoughts about Lily as each white doe twisted around them; but he knew better.
As the dementors closed in on him, he might have expected his last thought to be of Lily. But like his happy thought, it was of Minerva - and in another reality she lives, Severus.
Minerva...
The dementors sucked the life out of him, and he remembered the warmth of her body, and the kindness in her face as she looked at him that final time; and he hoped.