"Right. If that doesn't work there's an option for you in particular between getting away clean and suicide; he won't expect your singing trick and will ask questions, so you could sing your answers and hope he's usefully enthralled. But better to avoid him entirely. He probably won't be nearby. He has had enough contact with Yellow to make a transaction, but did not routinely visit or consider him a friend or anything. ...Also, if you see a tall silver-skinned blue-eyed fairy, also leave. You can still back out if you're scared."
"No, I can do it. Especially since those ones aren't even likely to be there. But I see why you say Fairyland is dangerous."
"Okay. First I'm going to make a gate to one of my trees, so I have a good place to put him; and if that settles right away, I'll make one to where his house was before I set it on fire; and if that settles right away too - in you go."
"You really don't have to do this if you're scared. It's not urgent. It doesn't have to be done at all."
Promise does nothing visible, then: "The gate to one of my trees settled..."
And:
"...So did the one to Yellow's area. When you're ready all you have to do is walk perpendicular to the floorboards, here to there."
She walks through, and starts singing. Just in case there are any fairies here.
The song, to anyone other than Promise, will convey the feeling that the listener doesn't urgently need to be doing anything right now, they can stay calm and stay where they are, and they especially don't need to be aggressive. It's not exactly a quality of the music, though she is also good at singing in the ordinary sense, more just an effect added on.
Trusting in that for protection, she advances farther from the gate and looks for any sign of habitation.
Her voice falters momentarily, but she's already using exactly the right song for this. She keeps going and increases both the volume and the power. She just has to find the fairy and get out.
"You ready to tell me? Because it took me fifteen years to make what you defaced and I can keep this up that long until you're ready to pay me back for that," she tells Yellow.
Yellow's response: incoherent sobbing!
If not, she can keep singing, run through some of her other songs when she finishes this one. As long as neither fairy changes the status quo, they'll both get gradually more susceptible until she can get in, get out, and get on with it.
She glances around, checking for other fairies. It shouldn't take long, minutes at most if she's trying, before they're in a daze. But they're really tense minutes, and her mental state matters here.
She moves around to the door, making sure she's loud enough to be heard without the window directly between her and her audience. (Yes. Audience. That's what this is. No different from singing under a spotlight in front of a crowd, certainly not anything scary.)
"Get off him. Move over there." She gestures, then remembers. "Across the room."
Yellow doesn't look like he's in a state to be ordered to walk. Can she carry him? Enlisting the torturer's help is probably possible, but that's the last thing she wants to do.
She picks him up—so much blood, how is he still alive, there's a reason she isn't a cape—and tells the other fairy "don't follow us." Then she resumes singing on her way out.