New orders. The mechanic stops dead instant, about faces, and silently retraces its steps, only distantly registering an absentminded frustration at yet another high priority request preventing it from finishing weeks old repair orders.

Prepare the ship for dive. It's already rerunning checks as it backtracks maintenance tunnels, climbs hidden ladders, and easily pulls itself out of spin gravity and into the deepest parts of its home, into the entrails of the host it symbiotes. Reactors, batteries, fuel rods, coolant stores, engines, magic drives all confirmed green. It's identified the dive apparatus as the only component requiring maintenance before any human would have even started inspecting the first item on the list.

By the time it's physically arrived, it already knows exactly what's wrong and how to fix it. It wastes no time, pulling itself apart into specialized tools, breaking the already unconvincing facade of a person as steel plates separate into thin, spindly appendages that would make a spider blanche. It inhales toxic smoke, makes note of the chemical composition and ratio of heavy metals, and exhales with a dissatisfied scoff. The Antarctica needs portside maintenance, not that it hasn't known that for days.

It pings the captain's console the all clear and within a second his voice blares through the ship like a siren. "All personnel brace for dive."

The mechanic pushes itself towards its host's nearest injury, resigned to staying within her core for the duration of the dive. It doesn't brace; the captain's words weren't meant for it. It isn't personnel, it's equipment; an accessory to its host, the only difference between it and her other organs being its ability to move through her.

The Antarctica tremors as she dips from one reality to the next, the cold, empty void of space giving way to the dense, hollow darkness of the abyss. Her dive apparatus buckles and screams as it struggles to pass an overload of magic from her drives to the spiraling shield that's keeping every living thing aboard from splattering against the walls and evaporating. The mechanic breathes in and tastes the poisonous air, and breathes out, and in, and out… this swimming, throbbing headache will pass. Either that, or the Antarctica's dive apparatus will finally give out this time, and they'll be left without crew, halfway between the void and the depths, waiting for two conflicting lawsets of physics to tear them apart, spending their final moments wondering what was so important that it demanded the capital that should have gone towards a higher-end apparatus.

Steel rends and splinters, steam and coolant bleeding from metal veins, hull groaning and cracking like dry skin. The mechanic feels its host's every injury as a new query on the stack, working through its worsening migraine to ease her pain at least a little. Her guts have become a pressure cooker, a cocktail of elements that even one of would instantly kill any human, but the mechanic barely pays it any mind as it fervently works to keep her functioning, laying supersealant over freshly welded cracks in pipes, redirecting coolant and stabilizers, pulsing radiation and magic through delicate instruments, breathing in, and out, and in, and out, and in…

The apparatus coughs and sputters to a halt, everything else slowing tempo to normal. The Antarctica’s homeostatic organ is now producing a steady whir as it maintains normal physics within her body, her hull holding fast against the strange pressure of the abyss. It’s badly damaged, but it should hold for the resurfacing dive; if not, a human will be sent to make emergency repairs – they’re more expendable than the mechanic. If needed, they’ll probably be sent out with simple scuba gear rather than a space suit – it’s all that’s necessary in the abyss, and it’s less of a loss in the event they suddenly disappear without a trace. The mechanic spends half a second wondering how the humans choose their sacrificial lambs after it’s finished calculating the optimal route between the most critical repairs it needs to make before the resurface.

The splitting migraine has subsided into a dull ache, gradually ebbing away as it heals each wound and resolves each query. Once it has its host ready to resurface, it moves on to the less urgent issues within her core. The damage to her hull is another annoyance on top of its ever-growing backlog, myriad injuries it feels as its own through its mental link with the Antarctica's on-board computer. According to the leading scientists, the mechanic, the Antarctica, and every other machine intelligence only receive information about structural damage as variables and flipped bits – it's nothing like real pain. The mechanic idly wonders what separates that from real pain. It hurts all the same.

By now the Antarctica's central organs are more or less spick and span. The mechanic pulls itself closer to her exterior to work on less vital repairs, since she's in no shape for it to be idling. It wonders what's taking so long for the order to resurface – the captain must be taking a long route. They're still within known deepspace, which means they're not lost and there's nothing to outright panic over. A large spacecraft has only disappeared from known deepspace… one time. It's going to be fine. In and out.

The mechanic has to mind its orientation as it reenters spin gravity, landing deftly on its feet and striding towards its next query without so much as skipping a beat. It's in human habitable corridors now, dealing with repairs it can't reach from the maintenance tunnels. It'd rather be doing other things in other places, but it wants to stay as close to the Antarctica's central organs as it can, so it can respond to the inevitable dive order quicker, and have her out of the abyss faster. She doesn't like the depths, and neither does it.

Crew gawk at it as they pass; it's a rare sight in these parts of the ship. It barely even registers them, entirely focused on its work, on its host. A human bumps into it as they pass by – no doubt intentional, given it's huddled against the wall and there's plenty of room. It doesn't look up, not caring for the distraction even slightly. It isn't disturbed again until its head buzzes with an order from the captain – Prepare the ship for dive.

The mechanic stops dead instant, about faces, and silently retraces its steps, suppressing its relief until it knows they're back in voidspace. It runs all the checks and finds everything green – it doesn't ping the all clear until it’s physically back in the core, in case anything might need its urgent attention during the dive.

The captain's order wails out again. "All hands brace for resurface."

Everything goes smoothly at first – as a rule, resurfacing is always less strenuous than the initial dive, since the ship is returning to the reality it was designed for, rather than leaving it. There aren't even any strain injuries for the mechanic to attend, at least not until-

It's completely out of nowhere. Some fault that was so minor as to be outside of the machine's knowledge or programming to even search for it, causing a horrific rupture – the mechanic's train of thought has already derailed under the immediate, overwhelming mental strain. It slams into the wall behind it as it blindly cradles its head, desperately trying to figure out what's wrong so it can do something about it- another rupture sends it reeling into the ceiling, which it bounces off, twirling through the air.

Hull breach. The Antarctica is already sealing off the relevant bulkheads; despite feeling the injuries more directly, she has a far greater volume of mental ability and pain tolerance. The humans in the area would have already perished the instant the dive shield faltered.

If nothing else, the second injury clues the mechanic into the nature of the first – the dive apparatus has sustained damage and isn't operating at full capacity. It wildly grabs onto a pipe and pulls itself towards the damaged organ- a second hull breach.

It's entirely given up on doing its job now, clinging to the pipes, its entire conscious mind just focused on keeping its breathing steady so its insides don't overheat. The Antarctica is now using it as a makeshift magic amplifier in a bid to boost her apparatus' output at least a little – she'd use crew as well, but she's programmatically incapable of willingly bringing any form of harm to them for any reason.

Every breath brings the mechanic closer to their mental link until it's all it can focus on; a side effect of the magic that coincidentally makes it more effective as an amplifier. It'd find the idea comforting if it could think straight.

The whole ship is writhing, threatening to split apart at the seams. The mechanic clings to her pipes tighter and sucks air deeper. Breath in, feel the steam flowing through them like blood. Breath out, feel the nuclear heartbeat of her reactor. Breath in, gasp for air as pipes all throughout her body rupture and spray aerosol lifeblood and superheated bile gas. Breath out, feel the pulsating ebb and flow of the magic coursing between her drives and mechanic and then into her apparatus. Breath in, breath out, breath in, breath out, breath in…

…

When the mechanic boots back up, several of its host’s wounds have already been repaired. She's back in voidspace. Relief washes over it.

It's a bit annoyed that it was put through a full reboot after the resurface, since it couldn't make urgent repairs in the meantime, but the amount of stress it was put through on top of the several hundred consecutive hours of consciousness prior would have been too much to recover from in a single sleep cycle.

Well, if one good thing came of this whole ordeal, it's that the Antarctica is definitely getting a new apparatus installed. The mechanic gets to work right where it woke up; humans can't survive in the conditions of her core and thus the crew could not make any repairs there while it was rebooting.

As it unfurls its forearm into a splay of welding implements, the mechanic muses that procedure should have been to keep it awake until all priority repairs were complete. It notices a ticket that was opened and immediately resolved right after it lost consciousness:

>mechanic unit stopped functioning[submitted by onboardAI(solved)]
RSN:mental break
FIX:rebooting to clear errors

It's a complete falsity. The mechanic is somewhat bemused that the Antarctica would lie over it. As it starts to resolve its stack of tickets, one query at a time, its gratitude is automatically transmitted to her through their mental link. She sends it an affectionate blip that makes its insides feel warm and fuzzy.

According to the leading scientists, machines don’t experience love or emotion; it’s all just simulation, just synthetic neurotransmitters running through artificial synapses. The mechanic thinks they’re all full of shit.