Anyway, the book is Consider Phlebas by Scottish author, Iain M. Banks.
A galaxy-wide war is raging between the Idirans and The Culture and has been going on for four years. The Idirans are an alien culture based on strong religious beliefs. The people who make up The Culture are of mixed heritage but tend to be more human based. They are very laid back in their approach to life believing strongly in not foisting your opinions or way of life onto others. They also rely heavily on a machine based technology.
Bora Horza Gobuchul - known to all as Horza - is a Changer, meaning he can take on the appearance of any humanoid he chooses, but not immediately, it's a gradual process that takes place over weeks. His natural appearance is human. When the book opens he's a prisoner about to be executed by drowning but is saved in the nick of time by the Idirans. It seems he's an Idiran spy and they have a job for him. The Culture's space vessels are run by 'Minds', basically computers which have a physical presence, and one of them escaped its ship in an attack and has taken refuge on Schar's World, a Planet of the Dead. The Idirans want Horza to go and fetch it so they can examine it and gain some technological advances.
The task is easier said than done. First of all Horza has to get to the far side of the galaxy and when he's captured by a 'free' ship manned by renegades it seems he has failed at the first hurdle. But Horza, at first demoralised, comes to see this as an opportunity if only he is willing to play the long game. And what a game! The crew of the ship are decimated by monks when they attempt to raid a religious site, hit an ice-berg on a mega-ship on a man-made 'Orbital' world, then Horza has to escape a cannabalistic sect on a desert island and various other trials before reaching his final destination. Then comes the biggest test of all...
I gave this a three star rating on Goodreads and am wondering if I may have been a bit mean. If there was a three and a half star option I would have chosen that because this was not a bad read at all. I just wish I had loved it rather than 'liked it'. It had all the right elements - it was imaginative, inventive, a roller-coaster type of a plot and so on. But somehow or other it just didn't do it for me and I'm finding it hard to put my finger on why. It's possible I just didn't connect with Horza. I was never really sure whether he was good, bad or somewhat indifferent. I know this is quite true to life, people do tend to be a mix, but my feeling was that he didn't care very much about anything and I found that off-putting.
The world-building, however, was superb. To be honest I think it's what kept me reading. I almost gave up I must confess, partly due to the small print of the book but also for my taste (your mileage may vary, as they say) the writing style was too meandering, too much superfluous detail. I felt the book wouldn't have harmed to lose 100-150 pages. Others would strongly disagree, I realise that! However, as I said, the world-building, or 'galaxy building' was excellent. For me the most interesting section was that of the Orbital world, Vavatch, which was mainly a huge ocean kept in place by giant walls. I imagined it like a giant polo mint, not sure if I got that right but it worked for me. A whole book set there would have been fine by me as that was by far the best and most interesting bit of the book.
It's an odd thing. Helliconia Spring by Brian Aldiss was equally as long as this book, in fact I think it may have been longer, but I didn't get bored once. Never felt the amount of detail (and there was a lot) was too much. Never found myself skip reading paragraphs. Was not glad to get the end. I know a lot of people think Banks' Culture series is the bee's knees in science fiction writing and I'm not disputing the quality of the writing 'at all'... he was (he sadly died last year) an amazing writer. But for me, something was missing. I can't work it out, I really can't, and will just put it down to individual taste and leave it at that.
Will I read any more in the series? I don't know. I'm intrigued by The Culture and may well pick another book up but the gaming plot of the next one doesn't really appeal. If I come across something in the library I may grab it and try it. It could be that I might like other books in the series a bit more as I'm not sure it's a continuous series, but more a series of unconnected books based in the same universe - a bit like Ursula K. Le Guin's Hainish books.
All in all a good solid read for the Sc-Fi Experience but not my favourite of the four I've read so far.