....You know, if Merrin is going to be deliberately inducing some kind of weird psychosis-adjacent imaginary people in her head situation, she...should probably have it balanced out. Since Kalorm is going to say stuff like "wouldn't it be EPIC to go swim in the ocean without a suit just to prove you CAN". 

She can imagine what her mom would say but mostly her imaginary mom is sad and worried so that doesn't really help.

She...actually seems to have a less clear sense of what, for example, some of her boyfriends would say; she seems to just fundamentally find it hard to run a mental model of people a lot smarter than her. (Not that Kalorm isn't on many metrics smarter than her, he's just...sufficiently strongly himself that the himself-ness dominates.) 

...She's already been doing all the mentally-writing-fanfiction. It's sort of easier to imagine characters, because it doesn't feel like she's trying and failing to accurately simulate someone who really exists in an objective sense. She can just. Have her own versions. 

Hmmm, who can she think of in fiction who's shiny to think about and also, like, would provide a counterbalance to Kalorm.... 

The bottomless night sky of stars twinkles above her head. The temperature is slowly dropping. 

Honestly most of the fanfiction Merrin has been writing in her head is on the premise of "what if I made this character very very sad and also very very horribly injured and they were my patient", which is not exactly optimized as a scenario to produce interesting imaginary conversations, even if she starts writing imaginary pretend fanfic about those characters abruptly appearing on this planet along with her and reacting to the same situation she's actually in. It's interesting to poke but nothing is as sticky as her imaginary Kalorm. 

- Maybe twenty hours later, after endless loops of free-association and moments of probably-microsleeping and a couple of food-and-water breaks and some swimming readjustment when the tide starts to turn and the currents spend a while very confused before switching direction, she finds something that's stickier.

The character in question is...honestly really hard for her to model, in the series he was constantly surprising her. Which is a lot of what makes it interesting to try now. He's from a weird kind of uncomfortable economicmagic setting where the author wrote a few hundred thousand words of auxiliary material to explain how it could be realistic for their civilizational equilibrium to be as much of a disaster as it is, and she would describe his trope as Complicated-Villain-Or-Protagonist-Depending-Whose-Perspective-We're-Taking-Here, and for reasons that the author also wrote several hundred thousand words of auxiliary material to explain, he is somehow the only person on his entire planet who has Solved Immortality With Economicmagic even though you would really not think this would be a stable equilibrium - honestly Merrin mostly skips and ignores the auxiliary material, she doesn't feel like it takes all that much suspension-of-disbelief to imagine a world with problems, if the world were made of Merrins it would have a lot more problems than dath ilan does - 

- anyway. He's interesting because of the - ruthlessness - and the determination, and he's...in some ways portrayed a bit like her? She's ever had the thought that he's sort of like if you took one of her boyfriends, and mixed in some of the Merrinish stamina and okayness with repetitive work - he's more intellectually curious than her, and has closer to the dath ilani baseline for liking somewhat zany overcomplicated plans because they amuse him, but he's sort of by authorial fiat portrayed as able to tolerate boredom in the service of long plans - but kept the ambition, against a backdrop where this was bizarrely unique. 

And he's a character who's portrayed as often operating alone. It's more possible to imagine him in isolation, without any of the relationships specific to the fiction series, whereas Merrin finds that a lot of characters just don't really feel like they hold together in her head if she takes them so completely out of their fictional environment. 

She is going to sort of mentally delete the sex drive. The number of sexy scenes in fiction that appeal to Merrin is a small fraction, and for this series, like many, she mostly skips them and so is missing that entire component of the charactermodel. ...She's also inevitably going to end up not really fully modeling the zany-overcomplicated-plots-for-amusement, because she isn't really like that at all...

If she imagines him abruptly appearing on this planet and needing to be dramatically saved by her, and then just being with her in the cave - ugh, it would really actually help to have the economicmagic, but she can come up with some weird contrived reason why he wouldn't have it - it's really effortful to figure out what he would say or do, but if anything that's what makes it interesting... 

His character in the series dreams of space travel, someday, after the contrived-ly horrible planet is in a better equilibrium. He would find it...interestingly meaningful, to achieve being-on-another-planet even by accident. 

And, of course, he's the complete opposite of Kalorm on the dimension of, like, willingness to risk True Death if it means he has freedom. He's really determined not to die. Merrin...could probably use some more of that in her head. Alone, she might be tempted to just...give up, at some point. 

...And eventually it seems like a reasonable time to go swim down and harvest her samples, and wrangle the mesh bags into the carrying-harness. She may have gone a little bit overboard; she's going to be hauling, like, forty kilograms of samples, more than half of it potential building material rather than food per se. 

Back at the surface, from a safe distance, she watches the tidal bore crash down the river-channel.

Her suit is still at almost 600 Wh of power, and her oxygen supply is holding up really well; she ended up setting the suit not to supplement her O2 while she was floating at the surface, and to just let her breathe 13.5% oxygen, she was fine. 

She waits another hour, maintaining her approximate position, and then she swims in with the tide. 

The predawn light is already in the sky as Merrin staggers out of the water and, somewhat unsteady even in her power-assist armor, stumbles up the riverbank and drags herself the last 600 meters to her camp. It wasn’t obvious how abjectly exhausted she was until she was once again subject to gravity.

…Merrin then proceeds to burn every single drop of willpower and stamina and determination she can squeeze out of herself herself to stagger back down to the rising tidal waters with her collapsible tub, fill it, and haul it back. She transfers all the possibly-edible-animal samples to it, in hopes of keeping them a "live catch" at least until she wakes up somepoint later today. She puts a plastic sheet over it to retain heat a little better, it’s -4 C in her tent, compared to -37 C outside, and to prevent them from escaping while she’s asleep.

Her armor is down to less than 100 Wh of battery life. Merrin struggles out of it and plugs it into the main battery, which is already picking up a trickle of charge from the first morning light hitting the solar panels up top. They'll auto-adjust for sun angle while she sleeps. She's so, so glad they're designed to do that. 

It's -2 ° C in her sleeping pod - it doesn't stay much warmer-than-ambient if she's not in it to produce body heat all night - but Merrin cannot stand the thought of being in her power armor a moment longer. She drinks some water, fails to find the energy to eat anything else, and stuffs herself into her sleeping bag. 

Ten minutes of shivering later, she's finally warm enough to fall asleep, and she passes out almost instantly. 

Sixteen hours later, the outside temperature is up to 28° C. The inside-the-cave ambient temperature is only up to a perfectly comfortable 14° C, but Merrin's cozy pod is warming up faster, and it's well past the point that the sleeping bag is necessary or comfortable. 

Hnnnnnngg.....? 

Merrin gets her eyes open, groans, rolls over to unzip the sleeping bag, and tries to prop herself up on one elbow.

OW HER ABS. AND ALSO ALMOST EVERYTHING ELSE. 

She's also SPECTACULARLY thirsty, and hungry, and in desperate need of emptying her bladder, and it STILL takes Merrin nearly ten minutes to slowly coax herself out of the pod and up onto her feet. 

...Possibly it is NOT SURPRISING that spending over 24 hours in the ocean, mostly ""resting"" but by a definition of "rest" that involved a lot of small semi-constant swimming-motion adjustments of her position, would use a different set of muscles than the ones already getting habituated to the gravity and all that. 

She has painkillers. She doesn't have a huge supply of painkillers, but she can afford a mild anti-inflammatory for today. 

And then! Time to check out her harvest!

The three giant-sea-snail samples she took back appear to all still be alive! They have adhered themselves to various spots on the interior of the tank, and it's quite difficult to pry them off but she doesn't quite need to get her knife out to accomplish it. 

This one, in its shell, weighs 2.47 kg. 

Merrin suspects at least half of that mass is shell, and not all of the insides will be edible - she's not going to eat, like, the digestive organs - but it's still a decent chunk of flesh!

...How...does she get it out of its shell....? It's still alive, and Merrin really strongly doubts it has enough of a complex nervous system to have experiences but she DOESN'T KNOW because it's NOT A DATH ILAN SEA SNAIL and what if life on this planet is developing on a totally different trajectory where everything has a nervous system and can have pain qualia? ...She's not going to start worrying about whether strapwrack plants experience pain, that sounds like a distraction from staying alive and also, like, deeply biologically implausible. But she's still kind of faintly squeamish about just cutting it up while it's alive. 

After some thought, she just takes it outside - in a plastic bag so it can't get a purchase on the rocks and snail-crawl away - and sets an alarm to get it in a couple of hours, at which point it should be frozen enough to be dead, and then she can heat some water with her tiny heating-element, not to cooking temperatures but enough to loosen it a bit, and then she'll dissect it out of there. Ideally she'd like to keep the shell intact, it might be useful. 

The snail is by far the most promising potential-food-source, but Merrin will sacrifice one of the bivalve samples while she's waiting for the snail to be removable from its shell! Bivalves really shouldn't have much more of a nervous system than, like, plants, and in fact - though probably mostly unrelatedly, not causally - it's also not triggering her brain's anthropomorphizing tendencies and so she is not feeling squeamish about it. 

.....Wow. That's incredibly unappetizing-looking, even though Merrin is STILL HUNGRY after eating two meal bars. She's recalling now that actually she kind of hates most shellfish, and separately what if it's full of heavy metals. 

- she should actually boot up her handheld X-ray spectrometer from the medical diagnostic equipment crate, and check. She can't detect weird algae toxins that way but she can detect mercury or cadmium or whatever.  

(Merrin has avoided using it so far for power saving reasons, but it's actually really power-efficient compared to her armor or the oxygen concentrator, and her solar power yield today is pretty good – she should finish today with her suit fully charged up again and with some power in the main battery to spare.) 

....That's the shell, which is as expected mostly calcium by weight.

(Merrin is also ignoring the direct spectrograph output, which she does know how to read directly but finds more visually-cognitively draining to interact with. She's programmed the system to give her NUMBERS in a TABLE like NORMAL LAB RESULTS.) 

She's not picking up on detectable levels of, like, lead or cadmium or mercury, at least not without waiting for a much longer analysis time, but what the FUCK is up with this planet's uranium content!!!!!!

(Merrin starts dissecting the contents out of the shell, to scan separately.) 

Why doesn't she know more astrophysics, she is TOO STUPID for DOING SCIENCE BY HERSELF ON AN EXOPLANET and is going to completely waste the opportunity to learn things that might keep her alive that is not a helpful thought. Laeirthe from her fanfiction (this author loved making up fictional names with way too many vowels and weird consonant-clusters in them) would find it very silly to waste time being upset about her starting conditions and resources even when those starting conditions and resources are the result of choices she made, and it's not like she had any way of knowing that an astrophysics background would ever be directly relevant to her life in any way. 

...She does think she vaguely recalls something about planetary systems being enriched with very heavy elements? Not supernovas, but....neutron star merger at the point when a gas-and-dust cloud was coalescing into a solar system? Maybe? 

Anyway. It probably has interesting predictions about what other elements might be present in unusually high quantities. Merrin will have to see if she can dredge enough basic nuclear physics out of her brain to figure out what, because she DOESN'T have a nuclear physics reference text unless she's completely forgotten about one she happened to save on her tablet reader. She does need to look up uranium toxicity levels, which will at least be in her on-topic-for-sims medical reference materials, but she doesn't think the ambient ocean content is likely to cause her any harm. Everywhere has background radiation all the time, and even in dath ilan it varies between locations by orders of magnitude and there's no clear data that the higher end of natural-ambient levels are associated with any health risks. 

What are the internal contents like? Merrin has now separated the flesh from the shell, and carefully dissected out the dark blobby organ that she suspects is a liver analogue and would therefore have a particularly high density of accumulated toxins. 

....Less uranium in the tissues, but this single 89 gram sample, which might if she's lucky contain almost 100 digestible calories, also contains almost 2.5x the maximum known-safe daily intake for a person of her weight.

(It's not the radioactivity that's dangerous at low doses. Uranium-238, the more common isotope, has a 4.5 billion year half-life, which is why there's still so much of it left on the planet. The radioactivity is really only a risk near huge deposits of ore, or - particularly - in cave systems overlying huge deposits of uranium ore, where its slow decay into radium and then radon gas will leave the gas leaking out of the rock and accumulating in poorly-ventilated regions. She should absolutely never go into a cave without the suit and a closed air supply, at least not until she's extensively checked on multiple occasions that a particular spot is reliably well-ventilated and never accumulates radon that would end up BEING ONGOINGLY RADIOACTIVE IN HER LUNG TISSUE. ...But uranium is, in fact, still a heavy metal, and it causes kidney toxicity at much lower doses.) 

No eating bivalves on this planet, then. Unless this one is a fluke, but she doubts it. 

...Both of her armored centipede-worm-fish appear to have died over the course of the day - maybe they're less resilient to temperature shock or pressure changes - but at least that means she doesn't feel bad about dissecting one immediately. 

Wow it has ACTUAL COMPLICATED INTERNAL ANATOMY.

Merrin is going to spend two hours dissecting it and sketching its anatomy, actually. Is this the most useful survival prioritization? Possibly not! But the imaginary voice of Kalorm is pointing out that she gets to do what she wants, and then there's a bit of an argument with the imaginary voice of Laeirthe-from-her-fanfiction about how No Actually It's Important To Maximize Odds Of Survival Though, but his conclusion is eventually that Merrin's morale is a critical limiting factor here and if she can find joy in dissecting weird not-crustaceans then she should do that. 

The intact centipede-worm weighed almost 2 kg. Merrin is eventually left with 680g of shell, 720g of organs, and 600g of pale, delicate muscle tissue. 

...She runs each component individually, muscle tissue and organ meat and the leftover shell, through her spectrometer. 

The shell has detectable uranium! Less than the bivalve, and it's not a calcium shell - it's presumably some kind of keratin-analogue protein matrix instead, though it fascinatingly has silica showing up as a significant subcomponent - but the probable-hepatopancreas-analogue organ has more uranium. 

The muscle tissue is almost clean. It does have more uranium content than one would expect in Earth sea life, but she could eat the entire 600 grams and only get up to half of her daily safe limit. 

....That might still be a problem, because the meat is probably almost pure protein and even that is going to be only 20-30% of the weight (the rest will be mostly water), so it might have 200g of protein, which is only 800 calories, and of course Merrin's daily safe limit is calculated for a 24 hour day but even then, she would be over it if she consumed her required 2500 daily calories entirely from centipedeworm.

...Also Merrin would have more serious problems because humans are not meant to run on protein as a sole calorie source, but hopefully she can find some source of fats and oils that isn't organ meat full of heavy metals.

She'll want to look to plant sources for her digestible carbohydrates. Her vague hope is that the deep-sea plants will have evolved to store accessible sugar and carbohydrate to use for cellular respiration during the long winter nights of no sunlight, and will thus have more sugars and starches than dath ilani seaweeds.

That, at least, is something her medical kit can test for. ...Assuming it's glucose or something else picked up by the glucose-strip test. If she's unlucky, all the sugars on this planet are the wrong molecular configuration or chirality and literally none of it will be digestible.