First published in Galaxy Science Fiction (May 1951 issue), by Isaac Asimov, and later in the French translation (issue #19, June 1955). Horace Gold, editor of the magazine, would include it in next year's anthology, Galaxy Reader Of Science Fiction. This Novelette is a Science Fiction story overlapping with the Spy Fiction genre, a Genre Mashup that Dr Asimov would repeat several times over, although he grouped them in the more general Mystery Fiction genre.
Dr Rose Smollett is informing her husband, Drake, that they will be hosting Dr Harg Tholan, an alien visitor from Hawkin's Planet, while he conducts a few Earth-based experiments. Drake doesn't appreciate opening his home to the Hawkinsite, so Rose placates him by giving him the information he demands about the alien doctor. She understands that policemen are naturally suspicious and isn't offended.
The first time all three are together, Mr Smollett has just arrived home for dinner. He exchanges polite pleasantries with Dr Tholan, and the three share a vegetarian meal together. Dinner conversation revolves around the alien; why he needs cyanide to breathe and what he studies. After dinner, Dr Tholan requests to visit a police station in order to see the human version, especially the missing persons department.
Each of these conversations were important; the unique nature of humanity, as defined by this story, makes them the symbiotic hosts to parasites. These creatures of mental activity derive nourishment from the mental activities of other creatures, and can exert a limited amount of influence over their hosts.
Once this information is drawn out of Dr Tholan, Mr Smollett kills him and explains to his wife why the parasitism has gone on too long; the human race is too adapted to the creature, living a symbiotic relationship where the absence of the creature causes cancer. Except that Dr Smollett knows that's wrong; cancer affects human children as well as fish that would otherwise grow the same way the aliens do. She quotes a line from The Bible,
"Hostess" has been adapted into an episode of X Minus One, and reprinted several times; Urania (published as a weekly serial; issues 33-36, from 30 January to 28 February 1954), Nightfall And Other Stories (1969), Urania (issue #568, June 1971), Robot Dreams (1986), Other Worlds Of Isaac Asimov (1987), The Complete Stories Volume 1 (1990), Tales Of Science Fiction Featuring X Minus One (2004).
"Hostess" provides examples of:
- Alien Blood: The aliens from Hawkin's Planet are yellow-coloured, six-legged space cows. Their blood is clear, and Dr Asimov goes into detail, explaining how the lack of metal in their bloodstream makes it colourless.
- Conviction by Counterfactual Clue: Mr Smollett, who works as a sort of "police officer" for the World Security Board, claims that humans have adapted too much to the non-physical parasite/virus to survive, citing cancer. In-Universe, Dr Smollett realizes that his claim is bunk, because while cancer is unrestrained growth (as opposed to the decay caused by the parasite), cancer occurs even in creatures which aren't hosts to the parasite. She's a biologist while he isn't.
- Double-Meaning Title: The title refers to Dr Rose Smollett, whose third-person perspective forms the basis of this story. The word "host" (or the feminine form, "hostess") refers to someone who is responsible for supplying hospitality to a visitor, or to an organism in which a parasite or commensal organism lives. She is currently hosting Dr Tholan, and all humans are host to a race of parasitic creatures with no physical form.
- Energy Beings: A parasitic intelligence, who has evolved away all physical traits, has supposedly evolved in a symbiotic relationship with human beings, making humans the only species in the universe who dreams, as well as the only species that dies of old age.
- Genre Savvy: Dr Smollett references "Twentieth Century spy novels and costume dramas" in her decision to conduct an investigation of her interstellar guest and her husband.
- Government Agency of Fiction: The World Security Board, who employs Mr Smollett as "a minor government official", but is more often described as a policeman. This implies his job is actually a secret agent, possibly an intelligence analyst.
- Have You Told Anyone Else?: Dr Tholan is shot as soon as he confirms that his theory (which Earth considers dangerous for humanity) has not been shared with anyone else. Justified in this case, because the methods that the scientist used to obtain the results are, among his people, considered as horrible as those of the Nazis. Also, he's fully aware he'll be shot... it's just that the alternative is far worse.
- Humans Are Special: Out of five known sapient species, only humans stop growing after reaching maturity. Only humans dream while they sleep. Only humans develop missing persons. Only humans die from old age. Dr Tholan assumes these facts must be linked, and comes to Earth to investigate the connections. He believes it is because a sixth intelligence also exists, one that evolved on Earth alongside humanity, as Energy Beings that feed on mental activity (dreams are a symptom of their feeding). Mr Smollett tells his wife that they are symbiotic, not parasitic, but his evidence doesn't support his reasoning.
- Humans Through Alien Eyes: The four-legged alien, Dr Tholan, thinks we look like we should fall over (he is a Heavy Worlder, and on his planet we would have fallen over).
- The Law of Conservation of Detail: The first night's dinner with all three characters implies several topics of discussion, but the only topics shown on-screen all become highly relevant to the conclusion of the plot.
- Mind Virus: In this story, humans are infected by a parasite that exists in their mind (it having adapted to not even needing a body). Dr Tholan speculates that many of humanity's unusual traits are caused by the existence of the parasite, including death by old age (other species simply live until accident or disease).
- No Biochemical Barriers: There are biospheres which aren't based on protein or even carbon, but the sapient species are all similar enough than an alien wanting to survive on human food only needs to bring some vitamin pills along.
- One-Word Title
- Orwellian Retcon: The version of this story as it originally appeared in Galaxy Science Fiction had mindless pseudo-genes infecting humanity. During some of the republications, it was edited into a species with no physical body that infected humans and aliens alike. When Dr Asimov republished this story for Nightfall And Other Stories, he removed the last line:Galaxy final lines: "She had finally learned why Drake had married her. Not a conjugal relationship— Conjugation."Nightfall and Other Stories final lines: "She had finally learned why Drake had married her."
- Serial Novel: This Novelette was published in four parts when it was translated into the Italian magazine Urania.
- Shameful Source of Knowledge: Dr Tholan found the cause for an epidemic on his world, but his method of collecting evidence would be considered Nazi-like for his species. Therefore, he came to Earth in search of further evidence that wouldn't be considered unethical.
- Shout-Out: Dr Smollett's internal narration quotes from the Book of Genesis, saying the serpent of Eden "was more subtil than any beast of the field." She compares the non-physical parasite of this story to The Bible, wondering if the myth was an Allegory for the parasite that causes "death by old age" in humans.
- Spy Fiction: Dr Smollett, aggravated by her husband's decision to withhold information from her, decides to attempt some amateur investigations of her own, imitating Twentieth Century spy novels.
- Ultra Terrestrials: Old age is the result of a Mind Virus, carried by either a set of mindless pseudo-genes, or a parasitic mind (it had been republished with a few edits). The parasite is compared with the snake from the Garden of Eden.