Now, this is what I call space opera: huge ships exchanging any number of ravening beams of destruction, implacable alien menaces, doomsday weapons, plucky heroines and heroes fighting desperate odds.Oh, yeah, this is the big time!All of the familiar elements of Reynolds’ fiction are here, from the miraculous but corrupted and decaying technology to the once-glittering but now rather rusty civilizations and the damaged individuals hoping for some sort of redemption. Not to mention the various clades of humanity still managing to survive, despite themselves.Redemption Ark is set in the same universe as Revelation Space and Chasm City but roughly half a century after. Thanks to reefersleep, time dilation and nanotechnology, many of the characters from these two books are still alive and well. Certainly the Inhibitors — lupine machine intelligences that seem to have patrolled our galaxy since it was young — are very much ‘alive’ and well. So well, in fact, that they’re beginning to turn their glacial attention upon the human race with a view to wiping us out, as they’ve wiped out all other intelligent life for millions of years.The Conjoiners, arguably the best (and certainly the most technologically advanced) aspect of humanity, are now split over what to do about the Inhibitor menace. Having secured their own existence by easily defeating the other main human faction in a pointless war, they’re now making contingency plans to secure an even longer term future. But the old warrior Clavain (whom some may remember from an earlier Reynolds story, ‘Great Wall of Mars’, in Spectrum SF 1) is suspicious of the motives of Skade, the head of this project. Why is there so much secrecy smothering the new Conjoiner technological initiatives? Why, after a century’s moratorium, has star-drive manufacture now been restarted? And what is the Conjoiner Closed Council so terrified of? (I’m not giving too much away when I say that it might be the Inhibitors).Meanwhile, on the planet Resurgam — Reynolds books always have more than one seemingly-distinct thread in them — where conclusive proof of the existence of the Inhibitors was first discovered (in Revelation Space), Ilia Volyova and Ana Khouri, late of the lighthugger ‘Nostalgia for Infinity’, have forced to change their own plans by the arrival of the first wave of Inhibitors in the system. Fortunately, the Inhibitors seem to be ignoring the regressive human colony — or are they just thinking bigger…?Redemption Ark is a great work of sf. We know Reynolds can write intelligent stories and build depressingly believable future societies, but now he seems to be getting the hang of writing realistic characters too. Clavain, in particular, is a likeable, intelligent and complex figure, but his opponent, Skade, is not simply a two-dimensional foil either. Both of them are striving towards the same long-term goal — it is mainly their methods that differ. Skade’s drive towards her goals, semi-exposed later in the book, eventually reveal her to be as much a victim as anyone.Similarly, the reasoning behind the Inhibitor mission — rather oddly, given that every character who encounters them speaks of their Lovecraftian evil — is shown to be morally rather more complex than, say, E.E. ‘Doc’ Smith would have allowed with his fearsome villains.As with all of Reynolds’ books, this is a long one. However, it doesn’t ever drag or feel padded out; rather it is exactly the right length. The ending leaves you sated but ready for the next installment. The end of Redemption Ark is only the end of the first skirmish in the war against the Inhibitors. I have the feeling that the best is very much yet to come…