Neurons are very slow by comparison to electronics.  They are still much faster than people.

But Thellim has been maintaining the Gift's advance instructions.

The first parts of Vanyel's tapestry to change, to go significantly out of bounds compared to past variation, are highlighted in Thellim's attention.  Thellim's focus goes into trying to maintain them in view, maintaining the current result of the instruction she tried to give Melody's Gift.  (The Gift will not simply obey an instruction to freeze its results without ongoing concentration; they tried that earlier and it didn't work.)

Thellim doesn't call out to Melody to follow the next step of the plan.  Melody should already be acting.  This has been rehearsed.

Melody is already rapidly scanning through everything that's bright-and-salient to her Sight, according to Thellim's specifications. Not that one - it's startle-response-related but not actually leading to the mage-control area of his tapestry - not that one either - oh, maybe this - 

She tries to highlight it back to Thellim, zooming in on it in their shared awareness - that looks like surprise or alarm, there, though it's not the emotion Vanyel would describe internally as that, it's too fast - it could be the precursor to Vanyel subjectively feeling startled, but the earliest step of it, to Melody, looks a lot more like the low-level, near-instant pattern that flashes through a person's tapestry if they, say, catch their foot under the edge of a rug that they didn't notice was curling up. 

(It is possible that the rug in Melody's patient room has a tendency to misbehave in damp weather, and that she has observed this exact thing happen a couple of times.) 

It doesn't just feed forward to Vanyel's emotions, though - something flashes across to the part of Vanyel's mind that controls his mage-channels. Melody can't see exactly what's going on there, of course, since she doesn't have mage-sight, but...it actually also looks a lot like the involuntary, instinctive clenching-and-stabilizing signal that people's minds send to their literal muscles if they're recovering from almost tripping on her stupid rug. Except metaphorically, with mage-channels. 

- and then a pain-response echoes back, within a fraction of a second, and it propagates to all sorts of places, but the one Melody pulls to the forefront of their awareness is where it loops back and triggers the exact same surprise-tripping error pattern - and then strengthens the signal going to Vanyel's mage-channels...

It's not entirely cascading out of control, since Vanyel's deliberate effort-of-will as he keeps the mage-light active is also linking to the mage-area, but the light is in fact oscillating a bit as he struggles to maintain the smooth control that was previously effortless. 

A wordless nod across the link.  This is taking all of Thellim's focus, plus 10%.

Melody would never in a thousand years have thought to Look in this precise way, but now that her focus is on it, she's practiced enough with Mindhealing to hold onto that without too much struggle.

:Huh. It's a loop again. ...Figure it's worth blocking it to see what happens?: 

With her Sight already on precisely the right area, she can do a temporary block in about ten seconds. She has no idea what the secondary consequences will be, given that the bit they're focused on doesn't exist in isolation and in fact links to all sorts of things, but if necessary she can reverse the change almost as quickly. 

Wordless more complicated dath ilani gesture of assent that will also come across as a nod.

:Testing something: Melody warns Vanyel, and then slaps down a very carefully targeted block. She feels a brief burst of satisfaction - she's never tried a block this precise before, but she thinks she got it spot-on. 

Vanyel yelps, nearly falling off his stool, and the mage-light vanishes, leaving the room dimly-lit by a couple of backup candles in wall sconces. 

:- What's wrong?: 

Vanyel takes a shuddering breath and rights himself on the stool, then lifts a hand and - looks blankly at it. 

:...I can't - I can't do magic?: he says helplessly. :Or - um, I maybe could but it's...like half my hand is numb? Except it's my mage-gift? Er, it doesn't hurt now but it did hurt a lot when you did it: Also he's pretty sure he lost a bunch of his reserves somehow, though it's hard to tell because, again, checking that involves his Gift and his mage-gift is not, currently, working very well. 

:Sorry! Fixing it: 

Melody rapidly undoes the block, at which point the snipped loop quickly snaps back into place, and Vanyel winces again but starts shakily re-casting his little mage-light. 

:- Thellim, do you have any idea what just...?: 

:hypothesis: feedback-channel causally-implicated in general magical dexterity:

:suggest: continue-iteration through previous-results for other-solution-candidates; do-not-try complicated-time-consuming repair-of-failed-solution:

:time-constrained:

Vanyel has his mage-light up and steady again, but he's also even more tensed-up and uncomfortable-looking than before. 

Right. Refocus. She broadens her Sight again, a little, starts scanning through the initial 'highlights' that Thellim's query turned up. 

:...Huh, no, I don't think this one is 'pain' per se: Zoom toward it for Thellim's benefit. :It goes into the same flinch pattern, I think? But it's not itself part of a loop. It's not fear or alarm either, not in the normal sense - it reminds me more of the basic startle response, but with a different flavour somehow - I think it might be 'expecting-pain', before there's actual pain? What do you think?:

:Gate:

:time-constrained:

:just-try-it:

:Trying something else: she warns Vanyel, and blocks it. 

In the first second or two, Vanyel doesn't really notice anything, to the point that he's not sure if Melody actually did it. 

...But, no, something is different. It's vaguely reminiscent of - hmm - of the way it felt at one of the awful crowded Court parties, when he finally managed to worm his way to a wall and find a nook where he could plant himself and watch, able to see anyone coming before they reached him, and it was never enough that he could entirely relax but it helped, and often gave him just enough breathing room that he could calm himself down over a few minutes. Finishing his camp-wards on the Border used to have the same feeling; it didn't mean he could entirely let down his guard, but it meant not having to be quite so vigilant, and then he could start winding down to sleep... 

:It did something: he thinks to tell Melody. :I think it helps: 

Melody can tell! She's stepped back her Sight-view a little, to get a broader sense, and - it didn't break the loop, didn't even immediately tamp it down, but it's starting to look like the pain-anticipation was one of the factors that was continually amplifying Vanyel's Gate response, and now that it isn't, some of the intensity of the clamping-down signal is fading, and the corresponding pain-signal returning from his invisible mage-channels is weakening. 

:...Seems like an improvement: she agrees. :Thellim?: 

Melody is very aware that it's been a minute, maybe longer, and Herald-Mage Savil is waiting on them with her Gate and will be more irritated each minute that they delay. She isn't rushing. As she learned a long time ago - and heard over and over and over from the other Healers, who were her mentors as much as anyone was despite not sharing her Gift - rushing is tempting, when you want to be as fast as possible, and it doesn't work. It predictably causes mistakes and sloppiness and having to redo your work. And, she reminds herself, Savil can and will hold the Gate for five minutes, and Melody can cope with a Herald-Mage being snappish at her if this is what Vanyel needs. 

So. Melody is definitely not in a desperate hurry. She's just trying to be efficient. 

:quickly scan remaining-candidates for better-alternatives:

She backs up and tries that. 

:- maybe this? Fear-anxiety pattern feeding back into the loop, I think, but...pretty sure it's a smaller factor and not sure we have time to conditional block both. Don't see anything else promising: 

Thellim lets go of her other results, starts staring at the primary candidate more closely, trying some queries she already came up with.  In parallel to that -

:Proceed with modification.:

:Vanyel, sorry, I need to undo the first block: 

It's in her way right now. She unravels it back to normal, then starts on something significantly more complicated. 

Ow. 

It takes Melody closer to an entire minute, this time, and her full concentration.

:Now: she tells Vanyel. 

Vanyel pinches his elbow. 

Melody had, apparently, never tried anything like this before today, when Thellim suggested it.

But she's practiced it five times in the last candlemark.

Melody even built the elbow-pinch connection in advance, and left the end ready to be connected, to save time; which Thellim herself hadn't thought of.

It is slightly less Manic Science.