Poderia ser Mundo da Morte 2 (também conhecido como The Ethical Engineer ) por Harry Harrison?
Um romance em vez de uma história curta e são os eletricistas com quem ele acaba.
Da wikipedia:
In Deathworld 2, Jason is kidnapped by the self-righteous Mikah, who is determined to bring him back to the planet Cassylia, ostensibly to be tried for his various crimes but really (because Cassylia does not want Jason returned, since his huge winnings in Deathworld have helped the planet propaganda-wise) for use by Mikah's movement to overthrow Cassylia's government, which they consider corrupt. He forces a crash-landing on a planet where the human population has regressed. The technology is extremely primitive and knowledge is split up among many small clans, each one jealously monopolizing what it knows. Jason uses his ingenuity to survive, trading his knowledge for protection and power in one of these clans. He eventually reaches the clan who has the knowledge of electricity and signals his location to a spaceship piloted by his Pyrran girlfriend, Meta.
A referência água que queima é do capítulo 12, onde Jason é sequestrado pelo Mastreguloj:
"Do you know to whom you talk?" the masked figure on the far right asked in a high-pitched, shaking voice. Jason examined the speaker carefully.
"The Mastreguloj? I've heard about you. You are supposed to be the witches and warlocks of this town, with fire that burns in water, smoke that will burn the lungs, water that will burn the flesh, and so forth. My guess is that you are the local equivalents of chemists; and though there aren't supposed to be very many of you, you are nasty enough to keep the other tribes frightened."
"Do you know what this contains?" the man asked, holding up a glass sphere with some yellowish liquid in it.
"I don't know, and I couldn't care less."
"It contains the magic burning water that will sear you and char you in an instant if it touches-"
"Oh, come off it! There's nothing in there but some common acid, probably sulphuric, because the other acids are made from it, and there is also the strong clue of rotten egg reek that fills this room.