The last day of the academic year. The last class, the last time they'd be sat together like this – at least, until graduation anyway. The sun was still beating through the window panes, turning the students into ants, sat sweating within the confines of their nest, while the windows became multiple parts of a giant magnifying glass. This promised to be one of the hottest summers Paris had seen in years, and if today was any indication of things to come, Enjolras dreaded the long days and weeks ahead. Within a few minutes, every seat was filled, all save for one – the one two along to his right, and the one whose owner was nearly shut out of the room before the class began. Courfeyrac was lucky in that he was good at talking teachers out of punishing him, and In this case, his half-assed excuse and apologetic face only just meant that he was forgiven.

The look he received from both of his best friends was returned with a boyish smirk, but soon enough, they were all being prompted into silence as their teacher began to speak.

"It's been quite a year, I think we'd all agree. And in that year, you've all been stretching your minds to the limit. You've been challenged, and you've argued with each other, and I've seen some very interesting interpretations in your essays. But, our time together is coming to an end. And there's only one way I can really think of to properly bring this year to an end…"

He looked around almost expectantly, glancing from student to student to see if any of them any ideas of their own. He saw one of the girls – Cosette – fanning herself with a piece of paper in a vain attempt to stave off the suffocating humidity. And towards the middle of the room, a note being passed from Grantaire to Feuilly – one that only got a poorly suppressed smirk from its recipient, and an eye roll from the stern, blond young man by the window.

"Since you're all a little distracted this afternoon, why don't I give you all a question; something to wet your brains before the exercise begins." The teacher tried once more, this time his voice raising just enough to command all eyes back on him.

"Think back across the year, back to the thought experiments we've conducted. I wonder…do we have any favourites?"

Finally, a response came from the front row, in the form of a pale, freckled hand raising to face height.

"The infinite monkey theorem"

The teacher nodded, somewhat gratefully. "The classic way to wrap your head around the concept of infinity. Refresh our memories, if you don't mind"

"Sure – it's the theory that infinity is so endless, if you put a monkey in front of a typewriter and let him tap at the keys forever, eventually he'll manage to type out the entire script of 'Hamlet' word for word. Of course, the odds of him hitting all the right keys in the exact right order are minuscule – less than that – but, cross time without any limit, mathematically speaking anything has a chance of happening."

"Why that one?"

Jehan shrugged with a shy smile. "I just find the concept of infinity fascinating. Absolutely terrifying, yes…but fascinating, ultimately"

"Fair enough – any others?"

"The trolley problem" Came another voice, this time from the far left corner of the classroom. This time, it was Eponine.

"A runaway trolley, or carriage or whatever, is hurtling along out of control. Further down the tracks are five people, tied down. However, there's a lever you can pull that'll divert the carriage onto another set of tracks, where only one person is tied down. Do you save the one, or the five?"

"Do what's best for the greater good." Enjolras piped up, arms folded loosely across his front as he looked over at the dark haired woman.

"Or at least, as far as utilitarianism preaches." Said Combeferre, glancing towards his friend. "Who's to say that one life isn't as valuable as the five you're saving?"

"That's not what's being presented to us." Enjolras replied coolly. "We have a choice to make, and I'm choosing to save the five. It makes sense."

"What if the other person was your beloved?" Called Grantaire, causing Enjolras to narrow his eyes, but humour him none the less.

"What?"

"Five people, or your dear Patria? Who's it to be?"

The obnoxious grin on his face was almost enough to make Enjolras rise to the taunt, though the exchange was quickly interrupted by Eponine once more.

"What about this; there's a morbidly obese man by the tracks, who you calculate to be just heavy enough to derail the carriage if you pushed him onto the tracks instead. Do you do it?"

"Of course not!" Replied Musichetta, turning in her chair to face the other girl.

"Why not?" Came Enjolras' voice once more. "It's no more acceptable than the first situation – it's still murder."

Had they not been under time constraints, the teacher maybe would have let them all start this argument anew. It was one of the first he'd presented them with when they'd all begun the year, and was evidently still one they were all divided about. Clapping sharply twice, the heated tones died down once more.

"Okay, okay – let's hear another."

"It's not so much a thought experiment, but the debates we've had over the existence of God have been pretty entertaining." Offered Combeferre, pushing his glasses up the bridge of his nose. "Or the question of whether or not we have free will?"

"Good choices, good choices...anyone else?"

Glancing around to check for other volunteers, Joly cleared his throat.

"The, ah…the ignorant bliss paradox?"

Prompted to explain why as his peers had, he swivelled in his chair in an awkward attempt to face all of his classmates at once.

"You're at the top of, say…Notre Dame, hanging onto the edge for your life. So, you call your three best friends to help you. They come running, but when they're faced with the seriousness of the situation, and the possibility of being pulled over themselves, none of them help you up. You fall…but inexplicably live. On the ground, you're elated you're alive, but are now faced with three people who you once trusted with your life who have shown themselves to not be worthy of that trust. Would you rather stay that way, or go back to how it was before? Would you rather go the rest of your life being friends with these people, not knowing your trust is somewhat misplaced?"

A sudden snort from the back of the room made them all turn. Giving Joly a smirk, Montparnasse sat forward, slowly lacing his fingers together in front of him on his desk. "'Somewhat'…that's cute. They let you fall from the top of Notre Dame. I say cut your losses. Fuck them."

"I agree. You can always find other friends" Said Marius.

"But from that point, you'd never be able to trust people in the same way" Grantaire added, offering his friend a theatrically doubtful expression.

"You have a good point…"

"I feel a 'but' coming on."

"But…" Smiled Cosette, "No two people are that alike in the world. There's no way of saying that your new friends wouldn't step up where your previous ones failed to."

"An equally good point – but! What are your chances that these new people are, In fact, trust worthy enough?"

"That wouldn't matter to you." Enjolras cut in, his tone sharp but weary from the heat. "You're incapable of believing in anything, let alone people."

"I believe in you"

"Oh, please-"

"I think we've all had enough of a warm up." The teacher cut in once more, sensing another argument already – the sort that wouldn't reap any sort of creative thought. To signal he was done, Grantaire folded his arms on the desk, resting his chin on his hands. Enjolras simply palmed a hand across his eyes and down the bridge of his nose.

"I want us all to imagine a global catastrophe; a complete and utter annihilation of the world as we know it."

"…How do you mean?" Asked Jehan, a curious frown drawing slight lines into his face. "Do you mean something like a viral pandemic? Or a meteor crash, or Yellowstone finally blowing up..?"

"There's a good one! Let's imagine Yellowstone park…but on a much larger scale. I'm talking the entire world coming to an end, as it were. How do you intend to survive?"

The room, for once, was quiet for a few moments before the late comer made himself known once again.

"I'd go underground, I guess"

"Underground…where? Do you have somewhere to go? Somewhere with supplies, fuel, oxygen?"

At that, Courfeyrac just smiled a little sheepishly as he shrugged. "Hypothetically I like to think so."

"Well, hypothetically, you do."

By this point, the teacher had everyone's attention, including Enjolras'. Waking his laptop, soon there was a sideshow of pictures being displayed on the board behind him. One by one, rooms were shown, all built in some 3D animation program. It was simple, but it put the message across. As he spoke, he occasionally clicked through the pictures.

"There's a bunker, specially designed for an apocalypse such as this. It has everything you could want; enough fuel, food, and water to last for a year. It's completely sealed off from the outside world, making it the perfect place to run to in the event of the world ending."

Pausing on one picture – this time of the dormitory – he looked around the room at each student.

"There's sixteen of you in here, seventeen including me."

"…But there's only eight beds." Combeferre stated, counting the beds in the picture once more to be sure. With a smirk, the teacher nodded.

"And this is where the fun part begins."