House of Suns   by Alastair Reynolds

Big ideas

The only realistic way for mankind to explore the galaxy is to clone oneself (shatter) into 1,000, not quite identical, parts, send them on different round trips around the Milky Way, and hold a reunion every 10,000 years at which experiences are combined and shared. In this universe a small handful of humans did this, each creating a `Line' based at some titular `House'.

Another Line of civilisation is a reproducing set of robots. There is one in the present universe, but an earlier one was wiped out by the book's protagonist Gentian Line; it was an accident, but the genocide has been masked for millions of years by the creation of a secret Line called the House of Suns. These are people who oversee through covert infiltration all aspects of the universe, and act to keep the dark secrets hidden.

But the last few of the original robots escaped the deathly man-made plague, and were instead trapped inside a star-dam, a device which entombs stars to prevent local populations from being obliterated by supernova explosions. Only this particular dam holds not a star, but the entrance to a wormhole which leads to another galaxy. It is believed that the remnant robot population would have thrived in this other galaxy, and now a massive population of them is about to come back and reclaim the Milky Way.

Local picture

Two of the shatterlings have formed a relationship and are circumnavigating the local galaxy together, an act almost unforgivable in the Line as it decreases the efficiency of the process of galactic exploration. On their journey they pick up a member of the modern robot population in a state of disrepair and with some amnesia. The big reunion is about to happen and they are a good number of years late for that appointment.

However, when they arrive at the meeting point they find it has been obliterated, along with all but about fifty of the Line of shatterlings. This results in a little murder-mystery novella, the end result being the elucidation of the big ideas described above. It turns out that two modern robots have learnt of the previous genocide, and planned on revenge by both wiping out Gentian Line and opening the star-dam to let the ancient population of robots back into this galaxy, presumably for total domination. The book ends up being action-adventure as the efforts of these two robots must be defeated.

Overview

The ideas and the stories that are woven around them are wonderful, realistic.

But there is one thread, which follows the early life of the original progenitor of the Line, which really has no connection with the rest of the book. It is interesting back-story, but ultimately it proves disappointing that this thread has nothing to do with any final reveal.

As with all Reynolds' work, the book starts out on a big plan, and then expands out by two orders of magnitude to even bigger things. Often this produces works which seem to be unbalanced, the latter part of the books seeming to betray the earlier reading effort. But not in this case. This book, as a whole, is a wonderful exploration of ideas on truly galactic scales, both in proportions of time and in those of space. This is the best book of his that I have read.