The ''Xeelee Sequence'' (; ) is a series of

hard science fiction Hard science fiction is a category of science fiction characterized by concern for scientific accuracy and logic. The term was first used in print in 1957 by P. Schuyler Miller in a review of John W. Campbell's ''Islands of Space'' in the Novemb ...

novel A novel is an extended work of narrative fiction usually written in prose and published as a book. The word derives from the for 'new', 'news', or 'short story (of something new)', itself from the , a singular noun use of the neuter plural of ...

novella A novella is a narrative prose fiction whose length is shorter than most novels, but longer than most novelettes and short stories. The English word ''novella'' derives from the Italian meaning a short story related to true (or apparently so) ...

s, and

short stories A short story is a piece of prose fiction. It can typically be read in a single sitting and focuses on a self-contained incident or series of linked incidents, with the intent of evoking a single effect or mood. The short story is one of the old ...

written by British

science fiction Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...

author Stephen Baxter. The series spans billions of years of fictional history, centering on humanity's future expansion into the universe, its intergalactic war with an enigmatic and supremely powerful Kardashev Type V alien civilization called the Xeelee (eldritch symbiotes composed of spacetime defects, Bose-Einstein condensates, and

baryonic matter In particle physics, a baryon is a type of composite subatomic particle that contains an odd number of valence quarks, conventionally three. Protons and neutrons are examples of baryons; because baryons are composed of quarks, they belong to ...

), and the Xeelee's own

cosmos The cosmos (, ; ) is an alternative name for the universe or its nature or order. Usage of the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity. The cosmos is studied in cosmologya broad discipline covering ...

-spanning war with

dark matter In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravity, gravitational effects that cannot be explained by general relat ...

entities called Photino Birds. The series features many other species and civilizations that play a prominent role, including the Squeem (a species of group-mind

aquatics Aquatics may refer to: *Aquatic sports in the Olympics and other international competitions, including the disciplines of swimming, diving, synchronized swimming, water polo, and open water swimming *Water-related sports more broadly (including boa ...

), the Qax (beings whose biology is based on the complex interactions of

convection cell In fluid dynamics, a convection cell is the phenomenon that occurs when density differences exist within a body of liquid or gas. These density differences result in rising and/or falling convection currents, which are the key characteristics o ...

s), and the Silver Ghosts (colonies of symbiotic organisms encased in reflective skins). Several stories in the Sequence also deal with humans and

posthuman Posthuman or post-human is a concept originating in the fields of science fiction, futurology, contemporary art, and philosophy that means a person or entity that exists in a state beyond being human. The concept aims at addressing a variety of ...

s living in extreme conditions, such as at the heart of a

neutron star A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...

(''

Flux Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phe ...

''), in a separate universe with considerably stronger

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

(''

Raft A raft is any flat structure for support or transportation over water. It is usually of basic design, characterized by the absence of a hull. Rafts are usually kept afloat by using any combination of buoyant materials such as wood, sealed barre ...

''), and within

eusocial Eusociality ( Greek 'good' and social) is the highest level of organization of sociality. It is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping generations wit ...

hive societies (''

Coalescent ''Coalescent'' is a science-fiction novel by Stephen Baxter. It is part one of the '' Destiny's Children'' series. The story is set in two main time periods: modern Britain, when George Poole finds that he has a previously unknown sister and ...

''). The ''Xeelee Sequence'' deals with many concepts stemming from the fringe of

theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...

and

futurology Futures studies, futures research or futurology is the systematic, interdisciplinary and holistic study of social and technological advancement, and other environmental trends, often for the purpose of exploring how people will live and wor ...

, such as artificial wormholes,

time travel Time travel is the hypothetical activity of traveling into the past or future. Time travel is a concept in philosophy and fiction, particularly science fiction. In fiction, time travel is typically achieved through the use of a device known a ...

, exotic-matter physics, naked singularities,

closed timelike curve In mathematical physics, a closed timelike curve (CTC) is a world line in a Lorentzian manifold, of a material particle in spacetime, that is "closed", returning to its starting point. This possibility was first discovered by Willem Jacob van St ...

s, multiple universes, hyperadvanced

computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...

and

artificial intelligence Artificial intelligence (AI) is the capability of computer, computational systems to perform tasks typically associated with human intelligence, such as learning, reasoning, problem-solving, perception, and decision-making. It is a field of re ...

faster-than-light travel Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light in vacuum (). The special theory of relativity implies that only particles with zero ...

spacetime In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualiz ...

engineering, quantum wave function beings, and the upper echelons of the

Kardashev scale The Kardashev scale () is a method of measuring a civilization's level of technology, technological advancement based on the amount of energy it is capable of harnessing and using. The measure was proposed by Soviet astronomer Nikolai Kardashev i ...

. Thematically, the series deals heavily with certain existential and social philosophical issues, such as striving for survival and relevance in a harsh and unknowable universe, the

effects Effect may refer to: * A result or change of something ** List of effects ** Cause and effect, an idiom describing causality Pharmacy and pharmacology * Drug effect, a change resulting from the administration of a drug ** Therapeutic effect, ...

of war and

militarism Militarism is the belief or the desire of a government or a people that a state should maintain a strong military capability and to use it aggressively to expand national interests and/or values. It may also imply the glorification of the mili ...

on society, and the effects that come from a long and unpredictable future for humanity with strange technologies. As of August 2018, the series is composed of 9 novels and 53 short pieces (short stories and novellas, with most collected in 3

anthologies In book publishing, an anthology is a collection of literary works chosen by the compiler; it may be a collection of plays, poems, short stories, songs, or related fiction/non-fiction excerpts by different authors. There are also thematic and ge ...

), all of which fit into a fictional

timeline A timeline is a list of events displayed in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events. Timelines can use any suitable scale representing t ...

stretching from the

Big Bang The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including th ...

's singularity of the past to the eventual

heat death of the universe The heat death of the universe (also known as the Big Chill or Big Freeze) is a scientific hypothesis regarding the ultimate fate of the universe which posits the universe will evolve to a state of no thermodynamic free energy and, having ...

and '' Timelike Infinity''s singularity of the future. An

omnibus edition An omnibus edition or omnibus is a book containing multiple creative works by the same or, more rarely, different authors. Commonly two or more of the works have been previously published as books, but a collection of shorter works, or shorter w ...

of the first four Xeelee novels (''Raft'', ''Timelike Infinity'', ''Flux'', and ''Ring''), entitled ''Xeelee: An Omnibus'', was released in January 2010. In August 2016, the entire series of all novels and stories (up to that date) was released as one volume in

e-book An ebook (short for electronic book), also spelled as e-book or eBook, is a book publication made available in electronic form, consisting of text, images, or both, readable on the flat-panel display of computers or other electronic devices. Al ...

format entitled ''Xeelee Sequence: The Complete Series''. Baxter's '' Destiny's Children'' series is part of the ''Xeelee Sequence''.

Conception

Baxter first conceived of the Xeelee while hobby writing a short story in the summer of 1986 (eventually published in '' Interzone'' as "The Xeelee Flower" the following year). He incorporated powerful off-stage aliens to explain the story's titular artifact, and in pondering the

backstory A backstory, background story, background, or legend is a set of events invented for a plot, preceding and leading up to that plot. In acting, it is the history of the character before the drama begins, and is created during the actor's prepara ...

began to flesh out the basics of what would later become the main players and setting of the Sequence: a universe full of intelligent species that live in the shadow of the incomprehensible and god-like Xeelee.

Plot overview

The overarching plot of the ''Xeelee Sequence'' involves an intergalactic war between humanity and the Xeelee, and a cosmic war between the Xeelee and the Photino Birds, with the latter two being alien species that originated in the early universe. The technologically advanced Xeelee primarily inhabit

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

s, manipulating their

event horizon In astrophysics, an event horizon is a boundary beyond which events cannot affect an outside observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive c ...

s to create preferable living environments, construction materials, tools, and computing devices. The Photino Birds are a

-based species that live in the

gravity well A sphere of influence (SOI) in astrodynamics and astronomy is the oblate spheroid-shaped region where a particular celestial body exerts the main gravitational influence on an orbiting object. This is usually used to describe the areas in the ...

s of stars, who are likely not aware of

baryon In particle physics, a baryon is a type of composite particle, composite subatomic particle that contains an odd number of valence quarks, conventionally three. proton, Protons and neutron, neutrons are examples of baryons; because baryons are ...

ic life forms due to dark matter's weak interactions with normal matter. Due to the inevitable risk of their habitats being destroyed by

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e and other consequences of

stellar evolution Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is consi ...

, the Photino Birds work to halt

nuclear fusion Nuclear fusion is a nuclear reaction, reaction in which two or more atomic nuclei combine to form a larger nuclei, nuclei/neutrons, neutron by-products. The difference in mass between the reactants and products is manifested as either the rele ...

in the cores of stars, prematurely aging them into stable

white dwarf A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place i ...

s. The resulting dwarfs provide them with suitable habitats for billions of times longer than other types of stars could, but at the expense of other forms of life on nearby planets. The Photino Birds' activities also effectively stop the formation of new black holes due to a lack of

Type II supernova A Type II supernova or SNII (plural: ''supernovae'') results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type ...

e, threatening the existence of the Xeelee and their cosmic projects. After overcoming a series of brutal

occupations Occupation commonly refers to: *Occupation (human activity), or job, one's role in society, often a regular activity performed for payment * Occupation (protest), political demonstration by holding public or symbolic spaces *Military occupation, t ...

by extraterrestrial civilizations, humanity expands into the galaxy with an extremely

xenophobic Xenophobia (from (), 'strange, foreign, or alien', and (), 'fear') is the fear or dislike of anything that is perceived as being foreign or strange. It is an expression that is based on the perception that a conflict exists between an in-gr ...

and militaristic outlook, with aims to exterminate other species they encounter. Humans eventually become the second-most advanced and widespread civilization in the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

galaxy, after the Xeelee. Unaware of the Photino–Xeelee war and the existential ramifications of what is at stake, humanity come to the (unwarranted) conclusion that the Xeelee are a sinister and destructive threat to their

hegemony Hegemony (, , ) is the political, economic, and military predominance of one State (polity), state over other states, either regional or global. In Ancient Greece (ca. 8th BC – AD 6th c.), hegemony denoted the politico-military dominance of ...

and security. Through a bitter

war of attrition The War of Attrition (; ) involved fighting between Israel and Egypt, Jordan, the Palestine Liberation Organisation (PLO) and their allies from 1967 to 1970. Following the 1967 Six-Day War, no serious diplomatic efforts were made to resolve t ...

, humans end up containing the Xeelee to the galactic core. Both humans and the Xeelee gain

strategic intelligence Strategic intelligence (STRATINT) pertains to the collection, processing, analysis, and dissemination of intelligence that is required for forming policy and military plans at the national and international level. Much of the information needed fo ...

by using

as a war tactic, through the use of

s, resulting in a stalemate for thousands of years. Eventually, humanity develops defensive, movable pocket universes to compartmentalize and process information, and an exotic weapon able to damage the ecological stability of the core's supermassive black hole. Minutes after the first successful strike, the Xeelee withdraw from the galaxy, effectively ceding the Milky Way to fully human control. Humanity continued to advance technologically for a hundred thousand years afterwards, then attacked the Xeelee across the

Local Group The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a " dumbbell" shape; the Milky Way ...

of galaxies. However, despite having annoyed the Xeelee enough to give up activities in the Milky Way, humans, having become an extremely powerful Type III civilization themselves at this point, prove only to be a minor distraction to the Xeelee on the whole, being ultimately unable to meaningfully challenge their dominance across the universe. Although the Xeelee are masters of

space and time In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing ...

capable of influencing their own evolution, they are ultimately unsuccessful in stopping the Photino Birds. They instead utilize cosmic strings to build an enormous ring-like structure (which comes to be known as Bolder's Ring, or simply the Ring) to permit easy travel to other universes, allowing them and other species to escape the Photino Birds' destruction of the universe. The Xeelee, despite their unapproachable aloofness and transcendent superiority, appear to be compassionate and charitable toward the younger and less advanced species that inhabit the universe, demonstrating this by doing such things as constructing a specially made universe suited to the Silver Ghosts, who humans had nearly driven to extinction. Humans are likewise shown compassion by them and allowed to use the Ring to escape, despite their relentless long war against the Xeelee.

Novels

''Xeelee Sequence'' (1991–2018)

Not all printings included volume number.

''Destiny's Children'' (2003–2006)

Series of thematically-linked novels set within the main ''Xeelee Sequence''. Published by Gollancz.

Short fiction

Short fiction set within the ''Xeelee Sequence''. Below is an incomplete list.

Anthologies

Previously anthologized short fiction.

Limited edition novellas

Limited editions distributed by UK-based PS Publishing. ''Mayflower II'' won the 2004

BSFA Award The BSFA Awards are literary awards presented annually since 1970 by the British Science Fiction Association (BSFA) to honour works in the genre of science fiction. Nominees and winners are chosen based on a vote of BSFA members. More recently, m ...

for Best Short Fiction.

Old Earth (2004–2009)

Short stories published as "A Tale of Old Earth". Stories are collected in ''Xeelee: Endurance'' (2015)

Chronology and reading order

The novels in chronological order (as opposed to publication order) are given below. Some of the novels contain elements occurring at different points in the

. The story anthologies (''Vacuum Diagrams'', ''Resplendent'', and ''Xeelee: Endurance'') each contain stories taking place across the entire chronology. In 2009, Baxter posted a detailed chronology of the ''Xeelee Sequence'' explaining the proper chronological reading order of all the novels, novellas, and short stories up to that year. The timeline was updated in September 2015. When asked directly for a suggested reading order, the author wrote: "I hope that all the books and indeed the stories can be read stand-alone. I'm not a great fan of books that end with cliff-hangers. So you could go in anywhere. One way would be to start with ''Vacuum Diagrams'', a collection that sets out the overall story of the universe. Then ''Timelike Infinity'' and ''Ring'' which tell the story of Michael Poole, then ''Raft'' and ''Flux'' which are really incidents against the wider background, and finally ''Destiny's Children''."

Reception

Science fiction author Paul J. McAuley has praised Baxter and the series, saying:

Notes

References

External links

* Stephen Baxter'
official website
* The complete (as of September 2015

of novels and stories, hosted on Baxter's official website. * {{Stephen Baxter, state=collapsed Book series introduced in 1991 Fictional universes Cosmic horror Mythopoeia Novels about extraterrestrial life Stephen Baxter series Fiction about transhumanism Fiction about artificial intelligence Fiction about wormholes Fiction about consciousness transfer Fiction about immortality Fiction about the Solar System Fiction about time travel Works about the future Quantum fiction novels Dystopian novels