I don't know, I don't know... The background story is, of course, just my cup of tea: First contact (yay!) turns out to be second contact (oooh!) - the aliens have been here before, and they feel the need to atone for some wrong they did mankind thousands of years ago. So far, so awesome. They select, out of thousands of applicants, 21 'Witnesses' whom they send to a number of planets to, er, witness.
We follow a team of three Witnesses to Kular A and Kular B, where we are introduced to two very different societies through the eyes of the incredibly annoying Cam and the overly self-assured Lucca. Soledad, the only likeable character in the entire book, stays aboard as back-up and liaison.
Eventually Cam and Lucca witness what they're meant to witness (even though they disagree on its meaning) and go back home with the news of what they've seen. (Can't be any more specific without spoilers.) And then the whole book falls apart.
I didn't understand how the Witnesses' return was handled by the respective governments and scientific bodies, I didn't get the Atoners' stance of non-interference (they can't have felt bad enough!), and I couldn't fathom
why nobody told Cam to stfu already. I was expecting the second half of the book to centre on ramifications and big philosophical debates and attempts at answering the big WHY (...on earth did the Atoners do that and why are they lying about being able to reverse it now?), but none of that happened. Considering that the Witness programme (heh) was billed as something BIG and HUGE and IMPACTFUL, the whole thing just petered out into non-significance.
Pity. I wanted to love this, and I did, in the beginning, but I was left frustrated and not caring.
I wish there was another book centred on the society on Kular B. And then a cross-over with the Culture 'verse so Jernau Gurgeh can play kulith