Here is a perfectly ordinary red district in Anitam. Nelen parks his truck at the recharge station, and the next driver takes the handoff, and Nelen stretches out the kinks in his back and heads home.
"Your neighbourhood has been very hospitable to me so far and I wouldn't like to cause you any trouble."
"There are ingredients I could use to make myself heal faster by magic... pure distilled water is probably the easiest to come by. I can also use similar magic to heal other people but I don't know whether magical healing is a service you'd find useful, and the traces would linger much longer than the traces of the magic I'm using now. Potentially permanently, depending on the method."
"As far as I'm aware, only magic can detect this type of magical trace," he confirms. "I think your technology is ahead of ours in a number of ways, but the technology I'm used to has tried several ways to analyze magic without directly using magic and failed at nearly all of them."
"I see. And you're concerned that... if I leave the neighbourhood and teach magic outside it, someone might later find out that I healed some of you, and they'd trouble you about it?"
"You are - unprecedented in an important way - and the other castes will be very interested in providing you with whatever you want in exchange for your magical help and general goodwill. It may be - very hard to explain to them, quickly enough, convincingly enough - that you would like us to be let alone."
"I think I see what you mean. Hmm. How difficult would it be to conceal me here until I can learn the language well enough to leave on my own? It should be... from the progress I've made since I got here, probably between sixty and ninety more days before I can puzzle through complicated written instructions without help. But then once I get out I suppose I will have to explain where I learned the language, and that could bring troubles of its own."
"We can probably find copies of the instructions online and have someone explain it to you here, which hopefully would let you get through without serious mistakes. If you can be on your way before it's implausible that we only kept you long enough to fix your leg - does your healing magic not work on your leg? - that would be better than lingering for months."
"The magic I would use to fix my leg is natural alchemy, which requires ingredients, and generally more specialized ingredients the more complicated the desired result. I'm a good enough alchemist that if I had close to my own body weight in distilled water to work with, I could cut my recovery time from most injuries in half; to do any better than that, I'd have to start experimenting to find out the properties of local materials, and by the time I'd figured out a better method my leg would probably have healed by itself. I have other methods available for healing other people. In a catrastrophic emergency I could heal myself or someone else very quickly, but the magic would leave traces that would trouble me when I eventually found my way home, for reasons that... well, I can explain my delicate situation to you if you'd like. It would be only fair, since you've explained some of yours."
"The planet I live on is called Earth; its inhabitants are humans. The place where I was, for lack of a better word, born, is called Hell; its inhabitants are demons. Demons are much more innately talented than humans at many powerful kinds of magic, especially transmutation, and for that reason among others, humans are generally afraid of us. It's normally very easy to detect demons on Earth using magical senses, because the substance of our bodies has distinctive magical properties and so does our innate magic. I prefer to live on Earth, for a number of reasons, so I figured out how to construct a human body for myself using only natural alchemy and terrestrial materials; it has no detectable infernal signature because nothing about it is infernal. If I used infernal magic to heal myself, I would have to rebuild my body from scratch again when I got home, or the first person with well-developed magical senses who saw me would assume I had the worst of intentions and sound as many alarms as they could."