ngine City, the concluding book in the Engines of Light trilogy, is set in a distant part of the galaxy, the Second Sphere, where planets have life from throughout Earth's past, including uplifted species such as the giant squidlike "kraken," who navigate starships designed by "gods" and piloted by "saurs." The gods are vast collections of extremophile nanobacteria living on asteroids and comets. Cosmonaut Volkov was part of a group of 21st-century humans who flew the first human-built starship, built from information from gods, to the Second Sphere.
Accompanied by Lydia de Tenebre, Volkov arrives on Nova Terra, where he tries to convince the Academy of Sciences to determine why he appears to be immortal. Later, he tells the Senate Defense Committee that the "gods" have told him that a new race of aliens will be invading and urges them to built military defenses.
Meanwhile, Elizabeth Harkness and Gregor Cairns discover evidence on the planet Mingulay of spiderlike aliens not related to Earth, as well as a species of aquatic hominids (selkies) that say they were brought from another planet by the spiders. They and others of the original crew decide to go to the selkie planet to find the spider aliens, which might be the ancient race that uplifted the krakens and saurs.
On the selkies' planet, Elizabeth and the others meet the alien octopods, who are friendly and want to "join" the humans in the second sphere. They demonstrate their ability to infect humans with their bio-nanotechnology, giving them enhanced memories and making them essentially immortal. Elsewhere, Lydia discovers that the octopods, called multipliers for their ability to make copies of anything, have transformed the trader outpost.
Everyone returns to Novo Terra to try to stop Volkov. They arrive with their multiplier friends to find Novo Terra is a balkanized, polluted, industrialized planet with advanced space defenses that has destroyed the first wave of multipliers. They must somehow stop the war and thwart the will of the gods to assure the future of human culture in the Second Sphere.
A confusing end to an ambitious series
The Engines of Light trilogy, which began with Cosmonaut Keep and Dark Light, is hard science fiction on the cutting edge, imaginative in concept and ambitious in execution. Ken MacLeod, who has been called "the greatest living Trotskyist libertarian cyberpunk science-fiction humorist," is clearly a writer worthy of serious note.
Engine City has almost all of the elements needed to succeed as hard SF, especially in terms of original concepts. The uplifted kraken and saurs from Earth's past, the nanobacterial gods that apparently control the galaxy and the bio-nanotech multipliers create a fascinating background for a quest for humanity to find its destiny among the stars on the far side of the galaxy. Unfortunately, the clarity of MacLeod's prose is not sufficient to convey the grand vision that all this promises.
Like Asimov, MacLeod conveys much of his ideas and plot through extended dialogues among his numerous characters, but he lacks Asimov's clear and simple prose style. It is difficult to keep track of who is speaking, which character is which (especially since many have the same last names), or where the action is taking place. There seems to be little difference among many of the characters—even the extremely alien multipliers end up sounding just like the human protagonists. Everything and everyone seems perched on the edge between inscrutable and silly, and it's often hard to determine whether MacLeod is seeking to be silly or profound.
The success of the final book in an SF trilogy usually depends on the ability of the author to build to a grand denouement that ties up all of the questions and loose ends and addresses profound questions about the human condition and mankind's destiny in the universe. Engine City appears to be striving for just such an ending, but veers confusingly off course. After reading the final sections three times, I'm not sure exactly what happened and why.
