Clavain is a Conjoiner, one of humanity's splintered factions dedicated to acheiving a unified consciousness. They were also responsible for creating the drive systems which accelerate ships to just under light speed. For undisclosed reasons they stopped manufacturing drives over a century ago. Clavain is about to find out why. A notorious Conjoiner, he defected to their ranks hundreds of years ago and is still distrusted by a few of them, although his skills are unqestioned. After being chosen for a clandestine mission, he learns the Conjoiners are still manufacturing starships - but for a very different purpose. They're fleeing the Inhibitors, and before they leave, they'd like to reclaim some of their property. Namely, the incredibly destructive cache weapons Nostalgia for Inifinity stumbled across decades ago. Clavain has different ideas however, as he cannot bring himself to abandon humanity. It's time to defect again, and to reclaim the cache weapons for a battle against the Inhibitors rather than a rearguard action. His search leads him on a journy to Resurgam.
He's helped along the way by various characters. Antionette Bax is an independant starship captain who owes Clavain a favour, and the shadowy 'H' is a powerful figure who's supplanted the mysterious Mademoiselle. Readers of Reynolds stand-alone/prequel, 'Chasm City' will immediately realize and appreciate his true identity. There's also Scorpio, a porcine-human hybrid who's an accomplished street soldier from his persecution on Yellowstone.
Clavain's defection didn't go unnoticed. Skade, a special operative for the secretive Conjoiner group 'The Night's Council', is enroute to Resurgam ahead of him to seize the cache weapons, and she'll stop at nothing to mantain her lead. Clavain's also concerned about an entity called the 'Wolf', brought back in the consciousness of a Galiana, a Conjoiner on an outbound mission in uncharted space. He seems to be a representative of a race intent on destroying intelligent life throughout the galaxy.
Meanwhile, on Resurgam itself, Ilia and Khouri have gone to ground. With the threat from the Inhibitors building in response to sentient life, they're determined to evacuate the entire planet as soon as possible. Khouri works for the government under an assumed name, and together they begin to formulate a plan. A small problem includes their method of escape, the Nostalgia for Infinity. Now completely infected by a strange hybrid of the melding plague and a perversion of Captain Brannigan, the ship has become something of a nightmare. They can only hope to convince Brannigan to help them evacuate the planet before the Inhibitors live up to their name.
One of 'Revelation Space's strongest points was the sheer originality of the world Reynolds created. From declining Yellowstone, to the decaying Nostalgie for Infinity, to the enigmatic Hades, Reynolds created worlds we'd never have imagined before. Out of necessity, 'Redemption Ark' isn't such a vehicle of creativity, as much of the action takes place in locales from the preivous book. That isn't to say that's it's just more of the same, as Reynolds still has plenty to offer. The Conjoiners are fascinating, and chapters into their history as well as their technology make up a significant part of the book.
Perhaps most welcoming are the insights into the nature of the Inhibitors. More galactic history is explained, and achingly short passages are given over to the sub sentience controlling the cleansing operationg around Resurgam. It's truly enjoyable to have a narrative reaching millions of years into the past. The motivation of the Inhibitors are also explained, and it comes as something of a shock to the reader. Whether it's an enjoyable or disappointing shock is another matter altogether, and really depends on the expectations of the reader.
The characters aren't much better this time around. The returning characters from 'Revelation Space' haven't grown much over the intervening years, and a few of the new ones seem to be almost sidenotes. Even the characters that Reynolds has invested significant effort into don't manage to elicit much sympathy from the readers. It's hard to identify with characters who seem to act mainly to further the plot. Clavain's history is interesting, as is Antoinette's sideplot, but they don't serve to define the characters in any complex way. This isn't to say they aren't interesting, if anything it's the opposite. It's just difficult to identify with them, or feel any real concern about their eventual fate.
The plot development can be seen one of two ways. On a microcosmic scale, involving search for the cache weapons and Resurgam's evacuation - events move at a frantic pace. The underlying plot however, while explained much more thoroughly, doesn't advance at all. Humanity's battle against the Inhibitors hasn't evovled in any significant way. At times, 'Redemption Ark' almost plays like a novel outside the main plot threads - it explains elements, but doesn't go so far as to resolve them.
As mentioned earlier, the pacing of the novel as a whole is excellent. There's always something happening, and Reynolds manages to make each sequence more surprising then the rest. Even Clavain's year's long journey across the empty void is full of exciting scenes, while events back on Resurgam move a little slower.
'Redemption Ark' is a worthy sequel to 'Revelation Space', and fleshes out the epic storyline even further. Although it doesn't quite begin to resolve any of them, the pieces are in place for a titantic third volume. Reynolds remains a joy to read, and his worlds are delight to explore.