a drunken mistake forces the houses of Hogwarts into open war

All rights reserved to Victor Hugo for the charas, JK Rowling for the setting, and Vanessa Richardson for the myth retelling on parcast that I listened to today, and that, being personal catnip in this fragment, inspired this show.

Also, this is my first Enjornasse story, not only the first one I filked from parcast and the first Enj-drunk one. That's a lot of firsts!

After that, he was offered the prefecture of Slytherin.
Initially, Enjolras was an outstanding ruler, an outstanding leader. Unlike more warlike and supremacist Prefects who had preceded him, he promoted culture and universal well-being, advised by friends of all bloodlines he had in all three other houses, which he considered Slytherin's equals. Defense and conquest of privileges were less important during this period than development and stability. But, as the Prefect led his thriving dominion, trouble brewed in the common room of Slytherin itself. Everyone's good fortune was about to change...
Montparnasse considered himself another Loki or Tezcatlipoca, as Lord of Change through Conflict. He'd been watching Enjolras develop these reformations, and he hated what he saw.
"There he sits! Pathetic little mortal! Puffing himself up with Hufflepuffs?! Consorting with the enemy?! How dare he call himself a ruler, or a leader? If either of us deserves that prefecture, it is I!"
Season after season, everyone carried on, blissfully unaware of the passed-over Slytherin's growing rage. Meanwhile, the aforementioned simmered over his fair-haired roommate's success, until he could stand it no longer.
What Enjolras didn't realise was that even his refusals were part of his roommate's devious plan.
Prosperity returned to Slytherin House: the Quidditch Cup was won by team Seeker Montparnasse having caught all three Snitches and, as a result, many people in green and silver turned away from Enjolras, and treated the victorious Seeker as their leader instead. For the first time, Montparnasse experienced what it was like to be popular, and almost to be Prefect. And he loved every minute of it. However, the Seeker still had a problem; a certain blond stripling continued wearing that badge on his chest. And, as long as Enjolras remained a Prefect, some people would persist in following him. With that annoying thought in mind, Montparnasse began devising a scheme to take over Slytherin for good.
Meanwhile, Enjolras spent his days in passionate concentration. He was so devastated by the pressure that came with his position that he barely ate or slept. By purging himself, he hoped to find a way to save them. Then one day, after many months of pressure, Enjolras heard someone approaching. He looked over his shoulder and saw an otaku-like young man in a hooded anorak and thick-rimmed glasses, carrying a mirror.
"What can I do for you, if there is anything...?"
"I have something to show you; a picture... of yourself."
At the otaku's urging, Enjolras looked into the mirror. And, to his shock, he didn't see his own image. Instead, he saw the place where he was in the common room empty of reflection where it should have been.
"Oh... ah... Can this be true?"
"The mirror shows what it sees, Sir. But... There are many different truths... If you come with me, I can show you how to shape your own!"
Enjolras was shocked by the image in the mirror, and he was was eager to erase it from his memory. So he got up and followed the nerdy young man. He had no idea that the stranger was actually his roommate and fiercest rival... or that the otaku was luring him into a trap.
Coming up: a drunken mistake forces the houses of Hogwarts into open war.
Then one day, his roommate appeared as an otaku, and told the prefect to follow him.
Montparnasse took his rival to the signalman's cabin of Hogsmeade Station, where an attendant was waiting. Strangely enough, that person half-framed in the evening light wore the uniform of the railway staff but with a Slytherin scarf on top. The attendant painted Enjolras' face like an eighteenth-century noble's, and wove a beautiful ribbon into his hair, to tie it back. He dressed him in a kimono-like crimson robe of rich fabric, embroidered with gold thread and leaf motifs. When this was done, Montparnasse showed Enjolras his reflection once again.
"Thank these attendants! I look like a leader again!"
Enjolras was so pleased by his appearance that he called for a celebration. The usual restraints of self-control had slipped from his grasp. A group of attendants, equally attired, joined him and the alleged otaku in the signalman's cabin. They brought a sweet nectar, which they encouraged the leader to drink.
"Thank you, my friends, but I cannot accept. I'm a Prefect, and a disciplined one. I'm not used to... indulgences of the flesh. Even a sip of wine or butterbeer could make me weak."
"Don't worry, Sir. It is not wine or beer they offer you, but medicine. It will help you reclaim your power!"
Enjolras still didn't realise that the otaku with the mirror was his scheming roommate. So at his urging, he took a drink of the nectar. Then, he took one more, and another. And a fourth. This so-called "medicine" was in fact an alcoholic spirit made from the alihotsy plant.
After a number of libations, the Prefect got extremely drunk! He began calling for his friends and other members of his Hogwarts house to join him.
"The-e-ere you a-a-are, 'Parnasssse... mmmm, so beautiful... Come, 'ave a drink with me!"
"Don't be afraid, my beautiful..."
Enjolras was so overcome by the power of this liquor that he forgot himself and his vow of chastity. Overcome with desire, he stole a kiss from the so-called otaku, then slapped him in the face, then fell unconscious.
The next morning, Enjolras and the Imperiused "railway staff" awoke. They were all horrified by what had happened. The news of what the Prefect had done was already spreading through everywhere. Montparnasse watched in triumph as his rival's followers within Slytherin rose up in anger against him.
They demanded that Enjolras leave the prefecture, and asked Montparnasse to rule them instead. Just as the Seeker had always wanted.
With a heavy heart, Enjolras gathered his last followers (Combeferre and Joly, Ravenclaw; Courfeyrac and Prouvaire, Hufflepuff; Marius and Lesgle and Grantaire, Gryffindor) and abandoned the prefecture. He was convinced, as he tore out the badge and placed it in the left palm of his rival, that the Slytherins were headed for disaster, but he did not know how to save them.