HP: I got Transmigrated into the World of Magic [Chapter 101: Room! ] (Patreon)

"Don't hold your breath."

"You realize I'm going to ask you to dance tonight," I point out.

"Yes, I had assumed it was unavoidable," she says with the same hidden amusement.

"You are wise to dread it, actually," I say. "Despite Hermione's tutelage I'm still a horrendous dancer. I consider only stepping on my partner's toes once a great victory."

"Don't listen to him, he's not that bad anymore," Hermione cuts in. I realize they had stopped speaking back there; they must have been stunned into silence when Daphne hugged me. "He didn't step on my toes a single time yesterday."

"You've been practicing?" Astoria asks in surprise.

"Well, yeah," I say with an embarrassed shrug. "Harry has to dance in front of everybody—"

"Ugh, don't remind me," he says disgustedly.

"—and I am motivated to avoid putting my dance partners into the Hospital Wing," I finished. "It only makes sense."

"But where'd you get the music?" Tracey looks quite interested, and a quick glance at Astoria shows the same.

"That would be one of my secrets," I say with a mysterious smile.

Hermione chuckles and shakes her head. "You and your secrets, William."

Harry clears his throat. "Why don't we show them?"

I stare at him in surprise, then turn to the Slytherins with an apologetic look. "Excuse us a moment, please," I say, then I grab Harry and Hermione and walk a short distance away where I put up a privacy charm. I turn my back on them in case one of them can read lips.

"What's wrong, William?" Hermione asks.

"I just want to make sure we're on the same page," I say quickly. 

"I'm okay with showing them if they don't see you setting up the Room and we don't tell them about how it works. But even that's risky. Did you forget how bad it would be if certain people, including professors, find out about the Room?"

"I remember you saying that, but I don't remember being terribly convinced," Hermione says, frowning slightly at my tone.

"Besides, when Luna tried to get in, we found out she couldn't open it while we were in there."

I sigh. "If you tell the Room that you need to hide something, you'll find the Room of Hidden Things. There are at least two dangerous things in there, probably more. First, remember I told you where the lost diadem of Rowena Ravenclaw is." Harry and Hermione pale at that so I nod firmly. 

"Yes, the Horcrux, which is dangerous for either of us to handle, if it's not outright painful for Harry. Remember Ginny two years ago? There's another thing, too: a broken vanishing cabinet.”

“The matching cabinet is currently in the possession of a shady character. Vanishing cabinets allow somebody to travel between the two instantly, bypassing any and all wards between them."

"B-but what about if Professors find out?" Hermione asks. "How is that bad?"

"Remember the tattoo their Head of House has on his arm? Remember Quirrell?"

"But you said Snape's on our side, and Quirrell's gone!"

"The point is, Dumbledore is not perfect. If it gets out..." Obviously I'm thinking of Crouch/Moody here...I really don't want him to gain any sort of advantage over us whatsoever. 

The less he knows about how I'm helping Harry, the better, even though he's probably already dismissed the knowledge that I'm helping him as unimportant.

"Okay, okay, we'll follow your suggestion," Harry says. "It won't do any harm even if there is nothing to worry about, right? So let's go ahead and open the Room, and we'll keep how it works a secret."

Hermione bites her lip then nods. "Okay."

I drop the privacy charm. "Sorry about that, let's walk for a bit," I say, smiling again.

"This better not be a trap, Lerner," Zabini says, eyes narrowed.

Tracey rolls her eyes. "Come on, Blaise, I want to see."

"If this is dangerous at all..." Daphne warns, glancing at her sister.

"Oh no, not at all. We're just headed to a particular room. Follow me, please." I consider offering my arm to Daphne, but I feel like I lost some of the ground I gained earlier when I took Harry and Hermione aside. 

So I offer it to Astoria instead with a grin. "The view is beautiful from up here, is it not?"

"Lerner..." Daphne says in warning.

"Sorry, Daphne, I would have offered you my arm but you looked like you might hex it off," I say. "Besides, Astoria's my date and I wouldn't want to make her feel slighted in any way."

Astoria giggles and takes it, and we walk leisurely around the corner. Astoria and I are in front, followed by Daphne and then Blaise and Tracey. Harry and Hermione are at the back. 

We make it just out of sight of the normal entrance before Daphne speaks up. 

"Why are we walking so slow?"

I hear the faint groaning and grinding of stone in the background. "Enjoying the view, of course! But I made a mistake, we accidentally passed the entrance." I turn around and walk the other direction at a more brisk pace.

"But we didn't pass any..." Daphne trails off when we come upon Harry standing in front of the door smiling.

"Right this way, please," he says.

I take a moment to enjoy the gasps and expressions of surprise when we all enter the Room. 

There is a large, slick-looking dance floor in the center, a slightly raised stage against the far wall with a collection of musical instruments which I know are enchanted, a row of comfortable chairs along both sides, and decorative, plush red curtains cinched up all around the room. 

Hermione had hurried over to get the enchanted instruments going, but they weren't playing yet when the door melted back into the wall.

Daphne has her wand out in a second. "What's going on?" Blaise pulls his wand out as well.

"Oops, sorry, I suppose I should have warned you about that," I say sheepishly. "This is where we practice."