This is my first serious fan fic, and English isn't my first language, so please be gentle!
Do tell me if you spot mistakes, typos, etc...
If anyone is interested, having a betareader to proofread my English could be nice!
You don't need to have seen Don't Look Up or Seeking a Friend for the End of the World to enjoy this story, as Severus Snape and Mary Potter (fem!Harry) will encounter the events and characters of these stories and describe them as it is new to them as well. It will contain spoilers of these movies, so keep that in mind if you haven't seen them but planned to do so.
The idea is to take Don't Look Up, substitute Randall Mindy and Kate Dibiasky for Severus Snape and Mary Potter, add elements of Seeking a Friend for the End of the World, and explore their reactions and feelings when confronted to their inevitable mutual death, as they're stuck together throughout this mess.
Chapter 1 : The Discovery
Mary Potter was done with fighting. Done with being the hero. She earned a retirement from the battlefield, from the stress and responsibilities that came with being the Girl Who Lived. Having survived the killing curse twice, she was in a better position than most to know the true value of the life you only live once.
As a result, she indulged in small pleasures of life. She drank with moderation; Mary certainly didn't refuse a drink whenever it was offered. She also smoked cannabis more openly than she did in her summers spent at the Dursley's, where she stole it from Dudley. Back then, it had been one of the only secrets her cousin wouldn't snitch on her, as Dudley would get in trouble himself for admitting to owning drugs.
She had defeated Voldemort two years ago. Before then, she had been dead set on becoming an auror, something that seemed thrilling and epic at the time. Only after spending a whole year fighting against the Dark Arts and dark wizards, as well as all the troubles she had had to go through each year, she was sick of it. She had wanted a normal muggle childhood when she was ignorant of her magical heritage at the Dursley's, and once she had discovered this new world, she had wanted to be a normal Hogwarts student. Of course, Mary Potter had to be special in both worlds: a freak with supernatural events surrounding her in the muggle side, and a hero with too much burden on her shoulders in the magical side.
Ultimately, she wanted a stress-free, laid-back existence. Lately, it was a wish that had been granted. She was at last out of the public eye, enjoying her romance with Ginny discreetly. They had agreed that a same-sex relationship would be controversial in such a backward culture. She had also carried on her studies alongside Hermione. She had finally felt like a normal student, her last year was free of Defense Against the Dark Arts teacher trying to harm her.
Of course, it had to be short lived. That was simply her luck.
Currently, she was sitting in the astronomy tower during the night, taking notes and adjusting her telescope, as she was drinking some hot coffee to warm her in the cold winter air. After giving up on her dreams, she had decided to go with something more relaxing, interesting. At least, that was something she had already been curious about when she was still living a muggle life, before her Hogwarts letter had first arrived. She may not have cared too much with everything going on during her school years, but once the war was over, she picked it back up as a hobby, it impacted favourably the subject in her N.E.W.T. Shortly after defeating the 'Dark Lord' and completing her education, the Chosen One had applied to be Professor Sinistra's apprentice, and it had been accepted.
She was allowed to do research during the summer, at least then she was not disturbed by admiring students. But right now she was watching the stars during the Christmas holidays, which was almost as calm. New Years had been only a few days prior. She had the castle almost to herself, and she wished that during her time as a student, she hadn't needed the blood protection from her aunt Petunia. The Girl-Who-Lived quickly reminded herself that even without that important protection, she would have been refused to stay. They had refused Tom Riddle as well, after all. And he'd been an orphan in a muggle orphanage without a need for a blood protection against an adult.
She was looking in her telescope, softly humming a song by the Weird Sisters, when something in the sky caught her attention. She had seen that object before, a few times.
"You again?" she whispered to herself in the night's silence.
She briskly shuffled through her parchments until she found the relevant notes regarding it. She noticed it had moved, again. Excitement overwhelmed her as she realized she had possibly spotted an unknown comet. She immediately made calculations regarding its size and realized it was at least thirty miles in diameter.
"You're a big boy, aren't you?" she grinned to herself. She was eager to tell the news to professor Sinistra the next morning. Normally she might have notified her right away, but the professor was pregnant, and she thought better than disturb her sleep.
She did not expect that discovery to be the beginning of another adventure. Another adventure that had neither a hero nor a prophecy.
The next morning, she was sitting in a classroom with N.E.W.T. level students who were invited by Professor Sinistra discussing her discovery from the night before. The majority of them were muggleborn. It was one of the rare subjects at Hogwarts that was fully translatable from the muggle world.
Everyone was chatting excitedly about her new discovery. She realised that from an outside's perspective, they would all look like boring dorks. That's how she knew she was now an adult. A bit like a muggle feeling excited to buy a new vacuum cleaner.
"The size, as calculated by miss Potter, is around thirty miles in diameter," Professor Sinistra said, one hand on her belly. She was about eight months pregnant. "I think we should name it 'comet Potter'!"
Everyone cheered and clapped, Mary felt her cheeks grow red. She doubted she would ever get used to public attention, which was part of her motivation to not pursue a career as an Auror.
"I think I'll be mentioned enough in history books already!" she protested, but Professor Sinistra simply smiled sweetly in response. "I suppose I'd rather be mentioned in astronomy books though…"
One of the students raised their hands, "What about its trajectory, Professor? Will we get to see it closer?" he asked eagerly.
"Let's see." Professor Sinistra turned to the blackboard and wrote equations. That was a part of the subject that bored a lot of the half and pure bloods. To be fair, it also bored most muggles. Mary was not an exception either, a few years prior. She relied a lot on Hermione for help, but these days were over now, Mary had grown up and found that mathematical equations weren't as soul crushing as she thought. That said, it was nonetheless boring.
Ron would disagree that it wasn't dreadful. He had been disappointed in Mary's career choice. They had wanted to be Aurors together, but in the end only Ron ended up pursuing it. They were still best friends, and Ron understood that Mary was done with the stress of fighting. Another perk of studying astronomy was that Mary was hopeful that eventually she could teach at Hogwarts, which she had seen as her home for all these years. She didn't feel ready to leave it yet.
Her train of thoughts was interrupted when Professor Sinistra abruptly erased the board and started over. Mary now listened carefully, watching her write formulas hastily, but before she could fully understand them, they disappeared again with a flick of Professor Sinistra's wand. This went on two additional times before Professor Sinistra dismissed the students. Mary and the others looked at each other confused while getting up to leave.
"Not you, miss Potter. You stay." Professor Sinistra said with authority. Mary sat back down, waving goodbye to the students, with a sinking feeling of impending doom.
Mary was sitting in Professor Sinistra's office, her elbows on her desk, holding her head in her hands. She was feeling numb, barely hearing the conversation that was taking place next to her, between Professor Sinistra and the face of the minister of magic, Shacklebolt, in the fireplace.
"Are you sure?" he asked. "This thing is going towards earth?"
"Yes." Professor Sinistra replied. "In six months' time. I calculated at least ten times and came to the same conclusion each time. Miss Potter here also calculated it and came to the same conclusion."
There was a short pause.
"I believe it wise to inform the muggle prime minister. Do not move, I may need you for further information." he finally said before the fireplace returned to normal again.
Professor Sinistra quietly walked behind her desk and sat down, remaining silent for a long moment. Mary leaned back into her chair and looked at the ceiling, the conversation had been unnerving.
"I'd kill for a joint." she muttered, Professor Sinistra looked at her disapprovingly. "Sorry! It's just…" she stopped talking at her mentor's understanding smile.
It felt like hours before Shacklebolt's face came back in the fireplace, but it had only been about thirty minutes. He asked them what the coordinates of the object were, and its size. They gave the information, he left again. He came back at least twice more for further information that Mary thought irrelevant, and he mentioned that the prime minister was being especially stubborn.
"After discussing the matter with the prime minister, we came to the conclusion that the president of the United States needs to be informed, as they're better equipped to deal with a threat to the planet as a whole." he informed them. "We have arranged transportations for you, you have one hour to have your trunks ready to go to America. I trust you will tell no one about the comet, including your significant others. Be right here and ready then. Professor Sinistra, I need to talk to you in private, it will only take ten minutes."
Mary immediately got up to go to her quarters, leaving her mentor alone to discuss with Kingsley. Since Mary was now an apprentice and not exactly a regular student, she had her own rooms. Before opening her trunk she sent a Patronus to Ginny, to inform her she had to leave in a hurry for America for a 'project'. She really wished she could tell her what was going on, and she knew she was going to ask a lot of questions, but there was no time. She put her Invisibility Cloak in the trunk, she didn't go anywhere without it. She also put in a few potions that she thought could be useful, especially Dreamless Sleep. She reckoned it would be efficient against the time difference between the two continents in a potentially world ending stressful situation.
She was still feeling numb, everything seemed to go way too fast for her brain to fully comprehend. She was still not certain if she was dreaming or not. She wished she had time for at least one joint. That reminded her to put some in her trunk, but stopped her momentum when she remembered that if they went through customs she could be jailed.
Wait, will we go through customs? She wondered. That hadn't been discussed. She didn't even know how witches and wizards travelled long distance. Would they use a Portkey? Did the Floo system extend to North America?
She looked at herself in the mirror. Everyone told her, at every opportunity, that she looked like her father but had her mother eyes. It was true. Her eyes were fully her mother's, but the rest of her face was unmistakably her father's. That's what her father would have looked like if he had been born a woman. Her hair was as messy and wild as his, she had grown them long, past her shoulder blades. She'd used a fringe for so many years to hide her scar. She often pictured that she could paint her face like the muggle band Kiss and she would fit right in without the need of a wig or hours in a hairstylist's chair. Hermione's curls were also a whole other level of untameable. The hair was something the girls had bonded over: As she was thinking about Hermione, she kneeled to better arrange her things in the trunk.
She closed it and floated it behind her with a Wingardium Leviosa.
She knocked on Professor Sinistra's office door. It opened shortly afterwards, and her mentor stepped aside allowing her to step in. As she let her trunk down to the floor, she noticed that Professor Sinistra didn't have a trunk of her own.
"Aren't we going together?" she asked nervously.
"No, I'm sorry. I would have, but…" Professor Sinistra looked down at her belly and Mary understood. "But don't worry!" she added quickly, sensing her apprentice's apprehension. "You're not going alone. Minister Shacklebolt and I found someone knowledgeable enough to replace me."
Mary Potter let out a sigh of relief. She could face Voldemort, face her own death alone. But somehow, that was easier than facing a muggle American president and explaining to them how she found out through magical means that if nothing was done, the End-of-the-World would hit in six months.
At that moment the fireplace brightened and Shacklebolt instructed her to Floo to the Ministry of Magic, which she did. Once there, she was escorted to a muggle military airport. She was told that it would look better and more serious to a muggle president if she travelled the muggle way. She was also encouraged to change into professional muggle clothing. She transfigured her clothes into a white blouse with black trousers. She walked up the ramp at the back of the plane looking inside, it seemed big and empty. She wondered where she was supposed to sit, when movement on her left caught her attention.
Somehow, the panic of the situation, of the world possibly ending before the end of the year, hadn't been surprising enough yet in that chaos of a day. Because seeing Snape leaning on the plane's wall had almost thrown her on the ground faster than you'd see the comet hit you.