Helliconia basks in the glow of the Great Summer. The continent of Campannlat is now dominated by the Holy Empire, a loose religious affiliation between the three great kingdoms of Pannoval, Oldorando and Borlien. These nations find themselves threatened by the far less technologically-advanced but considerably more populous jungle and desert nations to the west and the even more savage tribes to the east. When King JandolAnganol suffers a humiliating defeat to tribesmen using firearms (bought at great cost from the progressive nations of Sibornal far to the north), he divorces his wife so he might seek a more favourable alliance by marrying a princess of Oldorando. However, the queen is a greatly popular figure in Borlien and by divorcing her the king enrages the native population, triggering political turmoil and military action that will have great ramifications for all of Helliconia.
Meanwhile, the crew of the Earth Observation Station Avernus have fallen into internal dissent and debate over the nature of reality and their own orders from distant Earth not to interfere with life on Helliconia. Rejecting this order from a world they can never see or return to, the crew hold a lottery with a grand prize: to allow the winner to visit Helliconia, so for the brief few months it will take for the planet's viruses and bacteria to kill him he can live under a real sky. The arrival of Billy Xiao Pin in Borlien's capital likewise triggers events that will have unforeseen consequences.
Helliconia Summer picks up the story of the world of Helliconia some 355 local years - more than 500 Earth years - after the conclusion of Helliconia Spring. The planet is not far from its time of closest approach to the supergiant star Freyr and humanity rules supreme over the planet, the phagor population reduced to slavery or forced to hide in remote mountain valleys. It is a time of great technological innovation, with firearms, gunpowder and cannons flowing south from Sibornal, but also of turmoil, with the doctrines of the Pannovalan Church stifling the advance of technology and science within Campannlat itself. Like its forebear, the novel mixes thematic elements such as the rise and fall of civilisations, the advance of science and the uneasy union of progress and religion, with a more traditional action and character-driven narrative.
Helliconia Summer, appropriately, sprawls luxuriantly where its forebear was more focused and constrained in narrative scope and geographical area. It is in this novel that Aldiss' achievement in creating Helliconia is best-realised, with lush descriptions of the world and its myriad animal life and human cultures in full flower. The main storyline is compelling, combining intriguing politics and well-realised (if not particularly likable) characters clashing over the fate of their kingdoms in the face of warfare, religious turmoil and arguments over the fate of the phagors, the dominant nonhuman species of Helliconia reduced by the heat into docile soldier-slaves. The relevance of having an observation station from Earth is also made clearer in this novel, with one of the Avernus crewmembers becoming an important character. There are also some intriguing mysteries, such as a murder mystery whose conclusion is ambiguous and a deeper one surrounding the changes in pauk, the bizarre ability of the Helliconian people to commune with the spirits of their ancestors after death, which provide much food-for-thought going into the third and final novel.
On the negative side, the book suffers slightly from its lack of focus compared to the first volume and also from a somewhat clumsy chronological structure, where the first several chapters take place in the present and then we rewind a year and move forward to where the first part began, then skip to after it. The story doesn't really require this structure and would perhaps have benefited from a more linear progression.
In Helliconia Summer (****½) Aldiss' grand ambition, nothing less than a history of an entire world and its peoples across vast chasms of time, becomes clearer and more impressive. The book is available now (albeit somewhat expensively) in the USA and will form part of the new UK Helliconia omnibus due on 12 August this year.