''Saturn's Children'', and its sequel ''Neptune's Brood'', are a pair of science fiction novels by Creator/CharlesStross, set in a universe where humanity has gone extinct and our robot descendants are the dominant civilization.

By the 23rd century Mankind has died out, leaving the intelligent robots they created to carry on as best they can. Independent and self-sustaining, the robots struggle to find purpose in their "lives". Freya Nakamichi is one of these robots: created as a SexBot, she now has no reason to exist (seeing as there are no more humans around to sex up). While visiting Venus, Freya gets into trouble with some high-ranking robots. With things getting too hot for her, Freya is thankful to find a courier job that will take her off planet. Unfortunately the package she's carrying turns out to contain an secret that many robots would kill to possess...or die to destroy.

There is a story, "Bit Rot", which bridges the gap between the two novels. It can be read [[http://www.antipope.org/charlie/blog-static/bit-rot.html here]].

The sequel, ''Neptune's Brood'', is set 5,000 years later. The story follows a mild-mannered "[[MechanicalLifeforms metahuman]]" named Krina as she searches for her sister on the water world of Shin-Tethys. Along the way she is abducted - then hired - by SpacePirates, stalked by a [[{{Doppelganger}} Doppelgänger]] assassin, and unravels the complex financial cons that permeate the interstellar economy. All the while she holds her own secrets about the "Atlantis Carnet", the key to either the greatest treasure in the galaxy or its greatest scam.
!! Provides examples of:
* AfterTheEnd: ''Saturn's Children'' explores a Solar System inhabited only by robots centuries after the mysterious extinction of humanity.
* AscendedFridgeHorror: Freya was programmed to be overwhelmed by lust at the mere sight of ''Homo sapiens''--how, [[DontAsk you may ask]], do you condition a robot to behave in such away? Later on in the novel, we find out that [[HumansAreBastards Freya's long-dead designers]] did so by [[spoiler:[[RapeIsASpecialKindOfEvil inflicting traumatic sexual abuse on her during her "adolescence"]].]]
* CloningBlues: In a robotic version, the protagonist of ''Saturn's Children'' is a sexbot who describes how she, and other AIs similar to herself are created. AI's with human level intelligence take as long as a human would to develop, so no [[InstantAIJustAddWater instant AI]], with one loophole: an AI can be duplicated easily. The standard procedure for artificial beings like her was to raise one prototype as desired than clone the AI into identical bodies.
* ContemptibleCover: The first edition's US cover of ''Saturn's Children'' was quite controversial, to the point where Stross himself apologized on his blog, basically saying "I'm sorry, it's not my fault". While technically a relatively accurate depiction of the protagonist (she ''is'' a SexBot after all), it does tend to give people the wrong idea about the book.
* FlatEarthAtheist: Most robots, based on design schematics and such, believe that they were created by human beings. A few, however, believe in [[StrawmanPolitical the holy doctrine of Evolution]], and its prophets [[CharlesDarwin Darwin]], [[RichardDawkins Dawkins]], and Gould.
* GhostMemory: The robotic beings can obtain the memories of their sibs (other individuals of the same model) by putting in the sib's "soul chip".
* GlobalWarming: After humanity went extinct, [[DoesThisRemindYouOfAnything waste heat from the nano-economy combined with indifference from the surviving robots to cause a runaway greenhouse effect on Earth]] (the Gulf of Mexico is described as having reached a roiling boil).
* GreyGoo: Neatly inverted--robots think of organic life as "pink goo," reproducing without limit.
* HeartDrive: Most robots have a personality chip to backup their memories/personalities. This can be used to keep them alive by transferring their mind to another body or to learn from dead "siblings." "Wearing" the chip of another robot for too long however can lead to their personality usurping the original owner's and as a back up can take months or years to be fully complete destroying another robot's personality chip is a good way of ensuring they behave themselves.
* {{Homage}}: Though not an overt comedy, ''Saturn's Children'' is a tongue-in-cheek homage/parody of Golden Age SF planetary adventure stories, as well as the works of Creator/RobertAHeinlein and Creator/IsaacAsimov (to whom the book is dedicated).
* HumanitysWake: The story is about humanoid robots living in the wake of humanity's demise.
** Amusingly, we find out in ''Neptune's Brood'' that humanity is resurrected by the robots...only to go extinct again. This happens ''several times''.
* HumansAreCthulhu: Humanity died out long ago and left behind a race of intelligent robots that took its place. ''Saturn's Children'' deals with a plot by a consortium of wealthy robots who are trying to recreate a living human, which could have cataclysmic effects on robot society because obedience to humans is still hard-coded into their programming. A military organization called the "Pink Police" is dedicated to ensuring that something like this never happens.
** Completely averted in ''Neptune's Brood'': the robots have developed further and no longer have obedience hard-coded. They've resurrected humanity several times but we keep dying out. As such, they refer to us as "The Fragile" and view us with a kind of pity.
* IShouldWriteABookAboutThis: At the end of ''Saturn's Children'', we learn that the book we have just read is a message Freya is about to send back to her sisters on Earth, to warn them that [[spoiler:their supposedly long-dead mother Rhea is still alive and dangerously insane]].
* MercurialBase: In ''Saturn's Children'', there is a city on Mercury that's mounted on tracks that stretch around the planet, and which follows the terminator to avoid getting too hot or too cold. The protagonist's enemies [[spoiler:[[ChainedToARailway tie her to the tracks]] and leave her for dead]].
* MyEyesAreLeaking: In ''Saturn's Children'', Freya is alarmed for a moment when her vision becomes blurred and she registers saline leakage; a surprisingly non-functional response to emotions programmed into her by her long-extinct creators.
* NonIndicativeTitle: For ''Saturn's Children'', while the plot takes place on several different planets and moons in the solar system, Saturn isn't one of them, and there are no children in the story. ''Neptune's Brood'' is set in a completely different solar system, though it ''does'' involve a water world.
* NotUsingTheZWord: ''Saturn's Children'' justifies this by explaining the actual term "robot" is considered a FantasticSlur. ''Neptune's Brood'' shows that their technology has advanced to the point where they're basically advanced MechanicalLifeforms (with actual mechanical cells, analogous to our biological cells). They just call themselves "metahuman", and refer to regular humans as the "Fragile".
** The word "robot" came from the Czech word "robota" meaning "to work," and to avoid using "the R-word," menial or otherwise-limited mechs are called "arbeiters." Which is just the German word for "worker."
* PersonalityChip: Robots have "soul chips", which contain not their personalities, per se, but a recording of their experiences and thoughts, so if one were to wear someone else's soul chip, one to some extent wears that other robot's personality as well.
* PlanetOfSteves:
** In ''Saturn's Children'', Freya is "instantiated" from a line of robots who all have the same body and wake up believing they are the original bot, Rhea. They avert this by taking individual names. However, she then encounters The Jeeves Corporation, run by a line whom all refer to themselves as Jeeves. Later on, a specific Jeeves is referred to as "Reginald"; fans of Wodehouse won't find this helps the confusion much.
** In ''Neptune's Brood'' this applies to Krina Alizond-114 and her "sisters", who are all clones of their mother Sondra Alizond.
* PlotCoupon: {{Lampshaded}} via pun in ''Saturn's Children'':
-->"Don't get cute." He grinds the gun barrel against the back of my neck. "The encapsulated bird your conspirators sent you to fetch. The sterilized male chicken with the Creator DNA sequences. The plot capon. Where is it?"
* RidiculouslyHumanRobots: Justified. The (extinct) "[[ThankTheMaker Creators]]" never figured out how to program self-aware AIs from scratch. Instead they just copied the way human brains work. Played with in ''Neptune's Brood'' where the "robots" are advanced mechanical lifeforms with their own kind of biology and cells. The main character basically looks human, but many metahumans take other wildy different forms, such as bats, mermaids, or octopi.
* RobotGirl: Both novels, though ''Neptune's Brood'' to a lesser degree since Krina isn't necessarily a "robot" in the usual sense of the word.
* RobotReligion: PlayedForLaughs in ''Saturn's Children''. Some robots have examined all the relevant scientific evidence and concluded that robots were intelligently designed by a creator. Others fervently believe that robots evolved from simpler forms by means of natural selection, as described in their holy text: Darwin's ''Origin of Species''...
* RobotsEnslavingRobots: ''Saturn's Children'' is all about this. One of Freya's main worries is ensuring she always has enough money in the bank to never become another robot's property.
* SexBot: The protagonist of ''Saturn's Children'' is a sexbot in a world where humanity is extinct, making her existence almost pointless.
* ShoutOut:
** In addition to numerous {{Shout Out}}s to Creator/RobertHeinlein, ''Saturn's Children'' has a McGuffin disguised as [[TheMalteseFalcon a statue of a black bird]] and an organisation of robot butlers who are all called [[JeevesAndWooster Jeeves]] [[spoiler: one of whom has taken the name "Reginald"; Jeeves's first name in the books.]]
** In ''Neptune's Brood'', there is a pirate crew who call themselves [[Film/MontyPythonsTheMeaningOfLife The Permanent Crimson]], and who [[spoiler:turn out to be unusually aggressive insurance underwriters]].
* SpaceElevator: In ''Saturn's Children'', it's revealed that Mars has a space elevator called Bifrost.
* StarfishRobots: In ''Saturn's Children'', after the demise of humanity, the robots least attached to their creators have formed a new aristocracy, and the SexBot protagonist is despised for her DeceptivelyHumanRobot appearance. Most other robots have a more practical appearance for living and working in outer space or other planets. [[SuperDeformed "Chibiform"]] robots are described as being more efficient (in terms of mass and energy usage) than pure human forms, and the "metahumans" in ''Neptune's Brood'' take on a variety of odd forms, such as giant bats or aquatic creatures.
* TakeThat: While ''Saturn's Children'' is mostly AffectionateParody, there's a few swipes at Heinlein as well; WordOfGod is that the first impetus for the creation of Freya was to ask why anyone's [[Literature/TheNumberOfTheBeast nipples would go "Spung!"]], and there's two separate swipes at the "specialization is for insects" line - at one point Freya notes she ''can't'' do most of the things Heinlein's RenaissanceMan can do; as a generalist, her main ability is to find a specialist who can do them for her, and the colony ship requires lots and lots of specialists, and a few generalists to cover everything else.
* ThreeLawsCompliant: In ''Saturn's Children'', the robots were all basically created this way - in fact, the book quotes the three laws right at the beginning. However, with mankind extinct, the first two laws don't come up very often. In fact, the possibility of the first two laws complicating their lives is why ''some'' robots are so thoroughly opposed to the thought of trying to bring man back using genetic records and the like. [[spoiler:And more to the point, why a power-hungry cabal would be keenly interested in having a pet human to inflict on prospective subjects.]]
** It's a bit of a DeconstructedTrope: because the robots were created by mapping human neural nets, the first two laws have to be imposed afterwards. The methods used to do this are [[RapeAsDrama not pleasant]].
** By the time of ''Neptune's Brood'', this has apparently become a non-issue. The "metahumans" don't seem to have these issues and it's mentioned off-hand that humanity has been resurrected ''several'' times in the intervening 5000 years, apparently without issue.
* WhatMeasureIsANonHuman: Mankind is extinct, but the robots he created are still around, and still debating what rules apply to them.
* WhatWouldXDo: In ''Saturn's Children'', when Freya is posing as "the Honorable Katherine Sorico", she has to keep asking herself "[=WWtHKSd=]?"