"Space" is the second book in Stephen Baxter's Manifold trilogy, and a sequel of sorts to "Time", although it can also be read independently. Once again the central character is Reid Malenfant, an ex-NASA astronaut and failed entrepreneur. Obsessed with the search for extraterrestrial life, Malenfant seeks a solution to the Fermi paradox: given that the universe is billions of years old, if life exists out in the cosmos, why don't we see the evidence of it all about us? Thus when alien intelligence is detected out in the asteroid belt, Malenfant takes it upon himself to investigate, to make contact and ultimately to follow them back to the stars, through the mysterious blue portals through which they came.
The action unfolds over no less than 1,800 years, from the present day up to the thirty-eighth century, with the final, epic conclusion set another 5,000 years after that. In this way Baxter lays out a compelling vision of the possible long-term effects of Earth's contact with aliens. Unlike in "Time", where he employs an interesting mix of faux newspaper articles, blogs and journal entries to tell his story, in "Space" he sticks to a more conventional third-person narrative. The story is related through the perspective of four or five main characters, all of whom use the portals to travel to the stars and see life beyond Earth, and who, over the course of many years, become witnesses to the gradual decline of human civilisation.
The story is episodic in nature, and has the impression of a number of short stories loosely linked together. This can be frustrating for the reader, as there are enough intriguing ideas packed in this book to sustain half a dozen different novels. Each successive world is imaginatively drawn - from Earth, Io, Triton and Mercury to Alpha Centauri and far beyond - but Baxter tends to pass over them all very quickly, which does become tiresome. There comes a point about two-thirds of the way in when one wonders what the ultimate point is. Another result of the disjointed nature of the novel is that is difficult to feel fully engaged with the characters or get a sense of their development in these extraordinary circumstances. It is disappointing, too, that Malenfant - in principle a fascinating character - does not feature more, despite his centrality to the story. However, it is clear that this is not meant to be a character-driven novel so much as one based around ideas. Indeed "Space" has at its heart themes of human ambition and determination, consciousness and identity, self and soul, and the will to survive in a hostile universe, all of which are explored in depth.
In "Space", the author shows an imagination and consideration of the big questions of existence which is not often seen in most modern SF. It is true that there is less hard science and more scientifically-informed speculation than there was in "Time", but Baxter delivers it with such confidence that it hardly matters. This is truly a novel for the twenty-first century.