The plan is refined and strengthened, contingencies are set to deal with various ways Thorn could've strengthened his defences, Mortal receives a very interesting email concerning one of their mother's contingency plans—namely that her assets have all been either frozen or transferred to Mortal themself, so Thorn doesn't have access to them -, and when Mortal and Promise judge there's nothing more to be gained from further planning they (eat dinner, sleep again, have breakfast, go over the plan once more when it's not completely fresh in their minds so they see if they come up with anything new, purchase Promise a mobile phone and a power generator to charge its battery in fairyland, eat lunch while Mortal teaches Promise how to use that, and) part ways.
On this side of the veil, Mortal gets to work. The first step: getting at least two safe houses, one for their HQ and the other for contact with the place near Thorn's court. They end up getting five, for redundancy's sake. The main HQ is near Seattle, the other four safe houses are in Greece, Russia, Japan, and Argentina. That, and getting the necessary existing equipment, is the easy part—you end up with contacts of the relevant sort when the bulk of your wealth comes from the kind of thing you can get with sorcery. The hard part is getting the various specific bits of technology that don't exist yet, including the the many types of trap and ammunition they'll need. Processing fairy voices with software turns out to be a dead end—apparently they're weird magical superpositions of sounds that make software go ?!?!?!?!?—but everything else, as agreed upon, can be made to spec nicely enough.
It'll take a couple of weeks beyond the one month for everything to be ready. Mortal hires someone who talks very fast.
And after the ball's going, there's not actually much for them to do with their time. They fret about details of the plan, order more redundant pieces of stuff (especially the to-spec stuff, not being mass-produced means they'd better have a lot of it to start with in case anything goes wrong), and have various antsy and anxious and calm and relaxed and terrified and panicked moods. A month is a long time...
At one point it occurs to Mortal that Promise might've decided to run away and not help, and then they'd never see her again and that would be terrible, and why would it be terrible anyway? It's just some fairy, fairies are evil, one must remember that. Even though she wasn't, of course, she was smart and resourceful and moral and ridiculously hot, and if they never see her again she'll never order them again and the tingly feelings won't ever happen again. Except what the heck, what are they even thinking? The answer, of course, is that they want to see Promise again. Why? To save their mother, of course. The only reason being ordered like that felt good was because Science. Of course. Of course.
The month passes—
(Thorn needs to go into his room alone already, this needs to stop. Why is he terrible. Why is he so terrible.)
That's actually a good question. For now, paying attention, but later, she'll ask.
As soon as his door is closed and he's a few feet away from it: bullets. Lots of them, in a very short span of time. Invisible and soundless. The darts start darting at the same time, also invisible but not soundless, so as soon as they stop being deflected by the wards and clattering to the ground the mortal can stop chanting 'stop' and say 'sayyourname.'
No. Bad reaction. Not useful.
Second reaction: lower the bloody volume, he doesn't want to go deaf.
Third reaction: check that the traps are still trying to turn Thorn into Swiss cheese.
Fourth reaction: check resources. What are Verve and Sand doing? How are Promise and Yellow coping?
Sand is holding perfectly still, not even covering his ears, paused mid-step.
Yellow's covering his ears. Promise was on her sleep shift and is waking up now.
"Trapped Thorn, there's a ward on him that made a huge noise and apparently stopped Sand. Still trying to fill him with holes and juice."
The court's top-tier sorcerers burst into Thorn's room and find the trap and get to work destroying it.
"Okay, so not all is lost," he says, releasing a breath he hadn't known he'd been holding.
"If we had his name I could go in deaf and write fairylight orders, or you could..."
"But we don't, and I hesitate to send in Yellow or the person I hired" whose name has not been disclosed, of course "to do something like that. Yellow's as immortal as you are but there's a chance Thorn does have his name, and while he certainly doesn't have my employee's they're very mortal and very magicless..." He sighs, his eyes glued on the monitor.
Thorn has been healed. The room is being minutely searched.
The surveillance devices and speakers are quite small, and tucked away, but will of course on a thorough enough search be found. Both traps have run out of ammo by now and are inactive. Not much to be done about it.
"Sand doesn't have Thorn's name and he won't be able to hear you over the noise in the first place."
"I mean, after the noise stops. ...it'll have to stop, eventually, right? Or will he just plain sign everyone all the time or something?"
"It might continue until he knows how this happened. And has decided what to do about it."
"...okay, so, idea one is using Sand, unlikely to work. Then there's Verve, also a possibility. And then there's using the gate between the two courts, having a speaker somewhere there to yell at Thorn when he's passing through."
"But both of them have earbuds that can be much louder than they currently are and transmit messages from the mortal who is now Thorn's master! Maybe not loud enough they'd be able to be heard from farther than, like, a metre away if that, but it's still a resource at our disposal."