"There was the most dreadful noise I have ever heard."

"...okay, you try it?" she asks, handing her mother the notebook. "And then maybe let it go to see whether it starts affecting you again?"

Yeong purses her lips but does so. For science.

Kaede's curiosity did not appear out of nowhere.

When Yeong closes the notebook, Kaede's head starts throbbing, and she tastes blood.

Aaauuugh but is there actually blood there?

There is!

Her nose is bleeding now, too.

Yeah okay Yeong is opening that notebook again right now.

The blood stops, and Kaede feels her body relax.

"Are you alright, baby?"

"I..."

Well is she?

Nothing seems to be amiss now, she's recovered quite nicely.

"I'm fine," she concludes.

"What a dreadful object."

"Kinda," she agrees. "We're going to keep it like the others?"

"...I think perhaps this room could be a good place to stash these objects."

"Oh. Oooh!"

"The only problem I see with this solution is the possibility that this key may not be unique or that there may be other avenues of access to that room..."

"I noticed a thing, actually..."

She opens the door into the room again and walks into it.

Her mother follows her.

She messes up the bed, throws a pillow into the bathroom, then exits the room again, closing it after her mother.

Then she reopens the door.

The room looks exactly as it always does.

The bedsheet is neatly laid out, the pillow in its usual place.

"It resets..."

"Yeah, so the room's probably tied to this key."

"So if you put the notebook there..." She does, and closes the door.

And Kaede reopens it.