The spell goes up! 

It does not prevent the reactor from shedding heat; right now, it completes ignores all longer-wavelength radiation, which is a downside but makes it a lot more tractable. It does not reflect the drive plume back at the ship. It looks roughly like it should to Naomi's sensors. 

It's also taking a lot of impact from all the visible, near-infrared, and ultraviolet light that it does reflect. Light does not technically have mass but it does contain energy and, in some fundamental sense, those are kind of the same thing. 

(So far, at least from what Leareth can See, it's being pushed and deformed within the error bars of his predictions. Having the Proto is absurdly useful when one wants to do spatial-mathematical modelling of what is, approximately, just an engineering problem; the magic itself is way beyond what the still-small Proto can master right now, but the concept isn't.) 

Nayoki has NOT been running models with the Proto, and her surprise and shock are genuine - Leareth told her he would intervene 'at some point' but not that the spell was going to do something COMPLETELY UNEXPECTED - it's getting literally bent, into a shape much more like a flared cone than the neat cylindrical light-exit-path that they'd aimed for... 

:Leareth! LEARETH. Is this expected behaviour - should we abort -?: 

:Not yet - spell stabilizing... Need to check: 

And he flings all of his strength into probing more closely at how the vast working is holding up. 

(This is, in fact, ALSO something that he badly wanted to do, it's information he needs, he's the only one who can reliably work with the Proto on this.) 

(Whether the part where throwing his mage-gift around at full strength is definitely going to give him a seizure is an unfortunate side effect, or a convenient upside, is really just a matter of perspective.) 

The Healers, including the Proto'd one, swarm in close and check the autodoc. 

:Julie: Emril sends, urgently. :Leareth - has to do magic - does the machine think this is safe, can you translate -: 

"Uh, I can tell you whether it's trying to sedate him? It's - not yet - uh okay that's a warning - yeah it wants to sedate him now -"

:- Can you override it for ten seconds I am in the middle of something important -: 

Leareth is deep in trance, which makes it hard to tell how alert-and-oriented he is, but in Healing Sight his brain is definitely starting to do things that it shouldn't.

:- Cancel that, it should– Crap!: 

There is not a lot of leeway for Leareth, right now, in between 'worryingly close to the seizure threshold' and 'past it, already having a grand mal seizure'. 

:ABORT!!!: the Healer sends to Nayoki and Naomi both. :Leareth - medical emergency - need help–: 

...

Someone else is frantically reaching out to all of Leareth's mages, including the man currently guarding the spy, they need HELP with the spell-test - 

The mage in question has been engaging in friendly small talk with the spy, since he's supposed to practice the local language. 

"I - sorry - magic, emergency–" 

He slams the spy's door shut, slaps at the lock but does not, quite, actually, manage to lock it. And sprints. 

:Abort NOW: Nayoki snaps out, steadily and calmly but with emphasis. 

To Naomi, :- spell coming down - Leareth having medical emergency - need your help with the machines -: 

She lingers at the controls long enough to make sure the ship is behaving itself and that they haven't broken anything important. Once the ship looks intact she pings to wake the people on sleep shift and hurries after them down to the infirmary.

Leareth's people are skilled, and prepared. The shield-spell is carefully aborted and comes down, in a neat, tidy manner. 

The mage who was previously guarding the spy's door drops to the floor, his face turned away from the doorway and his eyes unfocused, as he joins the group-meld and adds his own strength to their blend.)

Leareth is, very unsurprisingly, now in the middle of having a seizure. 

The Healers are yelling at Julie for translations on the autodoc. 

"Can it sedate him now? It's administering a seizure med - it also wants him on oxygen - and a regulating implant but we can think about that in an hour probably -"

The spy walks out and heads purposefully for the Roci's transmitters.

Leareth's Healers hurry to follow the autodoc's instructions, as translated by Julie - one of them is also separately reaching for Naomi, who isn't currently sick and is thus a more reasonable answerer for questions - 

They approve the autodoc med-administration and get the oxygen set up. 

:Confirming test over - spell safely taken down: Nayoki sends to Naomi. 

And then she leans against the wall, on the bridge, and focuses most of her attention on Thoughtsensing the entire area where the spy is currently headed for the transmitters. 

The spy is worried it's going to be really hard to get back in his room, and the crew of the Roci was about ready to space him already, but the new people seem less inclined to, and their existence is obviously very important information that changes the odds the UN will, for example, just fire on the Roci, which they must at least be contemplating, depending what they know and who they know it from. 

He reaches the transmitters and is distracted from all of this by the urgent immediate problem of sending off a coded broadcast. 

A groggy Alex staggers to the bridge. "This had better be important."

"They tried their drive-hiding thing and I think the Roci's fine but Leareth had a seizure and they need help with the autodoc. Can you run a systems check?"

"Yeah." He starts this.

Squints, a second later, at the security questions. "Shit, Naomi, the prisoner's loose!"

She spins around in the medical bay and heads for the doors. "Where -"

Oh for fuck's sake. 

(This is within the bounds of what Leareth predicted might happen, at this point, and it's fine, everything is fine...) 

Nayoki listens in. Watches where Naomi is headed, tries to figure out whether any doors need to be messed with in order to give the poor spy enough time to get his message of - 

 - separately Mindspeaks the mage previously on guard-duty and tells him to run back to the prisoner's room and then frantically Mindspeak Naomi about how he was distracted for literally ninety seconds and the prisoner isn't there...