As the culprit behind the "dark magic accident," Ivy Doom's moment of self-satisfaction was interrupted by Professor Snape, who rushed in after hearing the news, just as Ivy had put several Slytherin upperclassmen into an uneasy sleep.
"Ivy Doom!" Ivy could almost hear Snape grinding his teeth. "What have you done?"
"Hmm—" Ivy decided to tell the truth. "A friendly, magical exchange? Don't worry, I just made them all fall asleep. No one was fatally harmed during this magical exchange."
Upon hearing the word "fatally harmed," Professor Snape immediately crouched down to check on the students. After confirming that none of them were in danger, Snape stood up, his expression returning to its usual impassive state.
"I didn't know you had this kind of ability, Mr. Doom?" Snape's voice was nearly a whisper before he started announcing Ivy's punishment. "Because of your... 'magical exchange,' for being too reckless, you, Ivy Doom, will be confined to detention for the entire semester."
Although Professor Snape was merciless, he didn't deduct any points from Slytherin, merely announcing Ivy's punishment.
"Sounds alright. At least Slytherin isn't losing points," Ivy calmly nodded, accepting Snape's verdict.
"Now, can I go back to my dorm?" Ivy raised an eyebrow and asked since Snape wasn't making any further moves. "I must say, it's been quite a fulfilling day. I'm exhausted. Especially after such an intense 'magical exchange.'"
"Hmph! As the first task of your detention, move these students to the hospital wing to receive treatment from Madam Pomfrey. Only then can you return to your damn bed," Snape refused Ivy's request and assigned him his first task. "Of course, I will supervise you."
"Wingardium Leviosa." Ivy extended his wand, casting a large-area Levitation Charm, lifting all the unconscious Slytherin students into the air. Then, he conjured a long rope to tie them all together.
"Shall we go, Professor?" Ivy politely asked Snape, leading the human balloon made of Slytherin students.
Snape didn't answer. He just flicked his black robes and started walking out of the common room. Before leaving, Snape noticed the first-year students still frozen in place.
"Has your brain been messed up too? Hurry up and get back to your beds! Also, I'd better not hear about any of you being late to class from any professor."
When the head of their house said this, the first-year students scattered like birds.
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"Fred! Look! So many Slytherin students are following Snape!" George pointed at the crowded names on the Marauder's Map.
"That's... Slytherin's dungeons?" Fred squinted, trying to recognize the location amidst the clutter of letters.
"What are they doing? Why are so many of them involved?" George started to wonder what was going on.
"I bet... Snape's unhappy about never getting the Defense Against the Dark Arts position, so he's taking the students to the Headmaster's office to protest!" Fred began to make wild guesses.
"No! It's worse than that! Maybe Snape wants to become the Headmaster!" George added, fueling the chaos. "This is war! Slytherin's war against Gryffindor!"
"Why Gryffindor?" Fred asked, not understanding.
"Because Dumbledore is from Gryffindor!" George folded the Marauder's Map and started to call his brother, "No matter what, we have to go and see what's going on."
"Of course. But be careful of Filch and his old cat. I just saw them lurking on the second floor on the map," Fred suggested. "Maybe we can go around the hospital wing. It's still early in the school year, and no one should be stuck there, so Madam Pomfrey won't be too alert."
"Right! Let's do that! I wish we had an invisibility cloak, though. That way, we wouldn't have to plan a route like this." George packed his things, planning to use some stink bombs as a greeting for Filch, but now their priority was figuring out the "Slytherin and Snape conspiracy," so not being detected was their best option.
"Don't even think about it. We can't afford that, and it loses its effectiveness after ten years anyway. It's nowhere near as useful as the Disillusionment Charm," Fred replied cautiously, peeking around the corner. After confirming there was no danger, he turned back to his brother. "We need to learn that spell this year!"
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Because Ivy was leading a human balloon made of too many students, it was inevitable that some of their limbs would get tangled with the decorations around the corners of the castle. Some bumped into paintings on the walls, while others got caught on armor's spears.
To avoid waking up the entire castle, Snape and Ivy had to stop every few steps and look back. They were hardly moving quickly. So, by the time they reached the last staircase of the dungeons, Fred and George had already been waiting for a while.
"My goodness... Did those students pass out? Did Slytherin have an internal war?" Fred and George watched in surprise as Snape's secret became clear to them.
But then they quickly realized things weren't good.
"We need to get out of here fast. Snape must be taking them to the hospital wing! If we stay here any longer, we're going to get caught!" Since they had come through the hospital wing to get to Slytherin's dungeons, their hiding spot was right in Snape and Ivy's path.
Luckily, Fred and George were as nimble as a pair of moving balls, so when Snape turned to urge Ivy forward, they seized the opportunity to slip away from their hiding spot.
"How on earth did those poor students pass out? Spending the first night of the school year in the hospital wing? I don't think we've ever done that," Fred and George successfully moved to the second-floor corridor in the main teaching block, continuing their discussion about what had happened in the Slytherin common room.
Before George could answer, the sound of Madam Pince's "meow" came from the end of the corridor.
"I know, if we don't leave now, we might end up with detention on the first night of school!" The two mischievous brothers hurriedly made their way back to their dorms.