Yuli is a child of a hunter-gatherer family living under the light of two suns on the northern plains of Campannlat on the frigid, ice-wrapped planet of Helliconia. When his father is enslaved by the vicious phagors, Yuli is left alone. He finds his way to the subterranean city of Pannoval, where he prospers as a member of the priesthood. Tiring of torturing heretics and punishing renegades, he elects to flee the oppressive city with some like-minded allies, eventually founding the settlement of Oldorando some distance away.
Fifty years later, Yuli's descendants have conquered a larger town, renaming it Oldorando as well, and are prospering. Game is becoming more plentiful, the river is thawing and warmer winds are rising, even as the smaller sun, Freyr, grows larger in the sky. But with peace and plenty comes indolence and corruption, and the people of Oldorando find themselves bickering and feuding for power, even as a great crusade of phagors leaves their icy homes in the eastern mountains on a quest to slaughter as many humans as possible.
The great drama of life on Helliconia is observed from an orbiting Earth space station, the Avernus, the crew of which watch as Helliconia and its sun, Batalix, draw closer to the great white supergiant about which they revolve and the centuries-long winter comes to a violent end.
Helliconia Spring (originally published in 1982) is the first volume in Brian Aldiss' masterpiece, The Helliconia Trilogy. In this work, Aldiss has constructed the supreme achievement of science fiction worldbuilding: Helliconia, a planet located in a binary star system a thousand light-years distant from Earth. Batalix and Helliconia take 2,592 years to orbit Freyr in a highly elliptical orbit (Helliconia is three times further from Freyr at its most distant point than nearest), which results in seasons that last for centuries apiece. Helliconia's plants, animal and sentient lifeforms have all biologically adapted to this unusual arrangement (in a manner that prevents colonisation by Earthlings, who would be killed quickly by the planet's bacteria), but its civilisations have not adapted satisfactorily: humanity rises in the spring and becomes dominant in the summer before being toppled by the phagors in the autumn and enslaved in the winter. However, more evidence has survived of the previous cycle than normal, and this time around those humans who have discovered the truth have vowed to ensure that humanity will survive the next Great Winter triumphant over its ancestral enemy.
Helliconia Spring is a complex novel working on a literal storytelling level - the factional battles for control over Oldorando and Pannoval, the phagor crusade flooding across the continent and the search for truth and understanding of the Helliconian star system by Oldorando's scientists - and also on thematic ones, with Aldiss examining the struggles between religion and science, between those who thrive in peace and those who thrive in war and the duality of winter and summer, humanity and phagor, and though the religious ritual of pauk, between the living and the dead.
Having the orbital Earth platform is a good idea, as it gives us a literal scientific understanding of the Helliconia system which those on the surface are struggling to understand, even if it does feel a little removed from the storyline at this time. Amongst other criticisms are a lack of character closure: whilst the grand history of Helliconia and the thematic elements continue to be explored in Helliconia Summer, the story itself moves on several hundred years, leaving the main characters of this book long dead. But these are outweighed by the strengths: the effective and impressive prose, the fantastic descriptions of a near-frozen planet thawing into life with its millions of species of plant and animal life waking up under the two suns and the impressive melding of cold, impersonal scientific worldbuilding with a satisfying plot and vividly-described characters.
Helliconia Spring (*****) is a masterpiece of science fiction and features the single most impressive work of SF worldbuilding to date. The novel is available now in the USA. A new omnibus edition of the entire trilogy will be published by Gollancz as part of the SF Masterworks collection on 12 August 2010.