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—
"Yellow doesn't have any sufficiently reliable claims to catch a fairy, and your name may not have propagated to all the same people as mine."
"Yeah, I know, but that's part of the reason why I hired another mortal to say things into a microphone when I ask them to."
"Yup, that's what I've been thinking. And also I asked them to tend to a little bean and take care of it and make sure it doesn't die."
"Does it need to be juice? I figured they'd provide regular juice and blend bits of the bean or beanstalk or whatever with the juice."
"It doesn't have to be juice but if it's not a thin liquid it might not inject right."
"If they cook it in water the resulting soup should work, though, presumably? This was just an idea I had to give them more of a claim on the food, since beans grow pretty fast, I don't expect it to make much of a difference anyhow."
"Yeah, something leached out of the bean into water should do it."
"Okay. But, er, there's still some stuff I don't have. Specifically the more sensitive various detectors with the shooting rig. They'll take a week or two to arrive."
"No, the better radar I already have, what I don't have is long-distance infrared, long-distance motion detectors, and some custom stuff that will use the combined information from all of those detectors to acquire a target and shoot it."
"Yeah, and so we have time to make sure there won't be any problems like weird fairyland interference with signal or what-have-you. And leaving cameras, radars, and sonars there, as well, to see what information we can get from the comings-and-goings between courts."
Nod. "Let's write it all up so I don't forget what I'm doing and have no reference -" She has paper; here it is.
The setup of the surveillance part of the plan, then, goes thusly:
Step zero: make juice and mix it all up, and put it in dart guns. Promise will be equipped with at least one of those, as well as an actual gun, plus the radar.
Step one: Promise goes through the gates to the spot where the original gate to London was. Using the radar, she finds the closest location to the closest court she's comfortable with, with as few obstacles between that location and the court as she can get. Up in the air is probably ideal.
Step two: she opens a gate from there to safe house 1 (the one in Greece).
Step three: she finds the second court, and does the same to safe house 2 (the one in Russia).
Step four: she finds a point between those two courts and creates a gate there.
Step five: she goes through one of the gates, and returns to her tree.
Step six: after the gates have settled, Mortal sets their equipment up to be partially through each gate, monitoring the locations.
Step seven: monitoring! Specifically, monitoring routes between the two courts, collecting information on any patterns in message delivery, and any other precautions Thorn may have taken they haven't thought of.
And most of the two following weeks will be spent on step seven, as Mortal continues to receive various delivered bits, and they watch and watch and watch.
Fairies travel in one direction or the other between the courts every couple of days.
And did Thorn, in fact, make them start going invisible? In groups? With any degree of unpredictability?
And eventually Mortal arrives at Promise's tree smiling and says, "We got everything."
"So, should we try to capture one of the probably-better-sorcerer-and-better-ward