Disclaimer: Had I been lucky enough to own Harry Potter, this would not be on a fanfic site. Nor would I be broke.
It was inevitable, perhaps, that this would happen. Albus had to admit that he had completely and utterly overlooked the possibility of something like this happening. Then again, he had been there for all seven years when James Potter and the other miscreants were abound. And he was somewhat certain that such a situation had not arisen then… actually, he was more certain that those four had never been caught at it.
He looked over his glasses, eyes sliding from one boy to the other. All five were fidgeting under the combined gazes of the Headmaster, their Head of House, and Severus Snape. Albus winced internally. Of all the possibilities, these five simply had to involve Severus's house. He sighed, before deciding to hear the incident from the five in front of him.
"Well, boys? Which one of you would like to start your explanations?"
Naturally, all five merely fidgeted more, not daring to look up to meet the gaze of any of the three professors in front of them.
"Perhaps, Harry, you should start. Considering, of course, the artefact used belongs to you." Albus motioned towards the Invisibility Cloak folded on his desk.
Harry looked up, only to meet the death glares of Snape and McGonagall. He immediately dropped his gaze once more, and tried to talk his way out of this.
"Well…sir… You see, me and Ron decided to explore the castle. You know, just so we could find passages to move around more easily…" Harry had to pause, attempting to find a good reason for exploring the castle, but thinking on his feet in front of the three professors was proving to be somewhat harder than he had imagined. Thankfully, he was saved by Ron.
"For safety reasons, of course, sir. You know, with Black around and all, we thought it would be smart to know of passages we could use to hide in and stuff."
Following that, Dean continued, "Yeah, and when Seamus and I saw these two about to leave, we decided to go with them. You know, just in case they came upon Black. Four wands would be better than two, no?" The four of them slowly started relaxing. They felt as if they might actually talk their way out of this mess. Sadly, they had forgotten to include Neville in their explanations, which left the boy to cast panicked looks at the others.
It was Seamus who decided to continue the tale. "And well, when we were leaving the common room, we saw Neville coming in, and decided to make it a Third Year adventure."
Albus continued observing each of the boys individually, but none of them spoke again.
"Then would any of you care to explain why you felt it necessary to bring this with you?" McGonagall sounded livid, as she picked up the cloak once more. "And where did you even get this, Mr. Potter?"
Everyone could hear an audible gulp from Harry as he muttered something under his breath.
"Might I suggest speaking up, Mr. Potter. Otherwise, we might feel that you are being uncooperative. And that would only serve to… worsen your punishment." While he himself was seething, having finally caught the Potter brat in a situation that could have him expelled was making him almost giddy.
"I got it on Christmas. First year."
McGonagall and Snape just stared at him, not believing that anyone would gift an eleven year old with an Invisibility Cloak. Albus decided that it would be unwise to allow their ire to fall on him, and so decided to prompt the five to continue their tale.
"Well, we eventually got lost, see?" started Seamus. "And then we heard these scary voices coming from one of the rooms in the dungeons, so we scampered off."
"And we saw these two older students walking into a doorway, so we all snuck into the cloak and ran in behind them."
"Honest, we never knew it was the Slytherin common room! Why would we even want to go there?" The glare from Snape was enough to stop Ron from continuing on that train of thought.
Silence descended once more, before McGonagall snapped at Neville. "You have not said a word, Mr. Longbottom. Do you not agree with your dorm mates… sequence of events?"
Everyone could see Neville's eyes widen in panic, and his breathing get quicker, before he gulped and stuttered out a 'no, professor'.
Harry decided to start off again. "Professor, we were in a common room we had no idea about, and we were all scared. The entrance sealed itself, and we weren't sure where it was. So we decided to go to a less crowded area, and we just ran up the stairs."
"And it just so happened that you decided to pick those stair, is that so?" Snape snarled.
"Honest, Professor! We had no idea where those led to!"
Snape was about to say something more, but was silenced by one look from Albus. The Headmaster felt as if he needed a bottle of mead to deal with this, yet he preserved.
"And then what happened, boys?"
The five glanced at each other, unsure about what to say, before Dean started answering. "Well, we thought we'd be safe, but we saw these two girls walking towards the stairs, and we bolted into the first open door that we saw."
"And that open door just happened to be at the absolute end of the corridor?" interrupted Snape.
"Yes, Professor. So we all just jumped in, and kept our mouths shut. We planned to sneak back out when curfew started. The door out of the common room would have kept opening for prefects and all, right? So we decided to just stay put where we were."
"And when you realised that the room you were in was actually the showers, why did you not decide to leave?"
The five once more glance at each other. There was no way they were going to be let off easy from this, but they had to try.
"We… well, we didn't notice." Came the reply from Ron.
The professors stared at the students, unbelieving that this was their defence for their actions.
"Allow me to recap, boys," started McGonagall, "you five snuck out, in an invisibility cloak, to find passages you could use to hide, in the off chance that Sirius Black managed to find his way into the castle, and managed to get lost in the dungeons. From where, you accidentally found yourself inside the Slytherin common room. At which point you decided it would be wise to run up the stairs to the female dorms. Not satisfied merely with trespassing, you then decided to hide in the showers, which was in fact occupied by 3 seventh years, and 2 sixth years at the time. Of course, you did not notice any of them. Is that a correct assessment?"
Four of them promptly nodded their heads, perfectly willing to stick with their story. Their unity was, sadly, destroyed when a red-faced Neville muttered out, loud enough for everyone to hear, "There were two third years as well."
Albus sighed. He could certainly use a bottle of mead now… or perhaps two. Then he considered that September had not yet ended. It was going to be a long year.
All five were assigned a month long detention, with two weeks being supervised by Professor Snape, and the other two weeks under Argus Filch.
The 7 girls were never aware that five third-year Gryffindors had seen them in the buff.
Some of you may ask how they managed to run up the stairs to the female dorms... Let's just say that each common room is different.
Please note, I used British English for this.
Thanks for reading!