Home Fires by Gene Wolfe

This one is a science fiction mystery/adventure, and because it is a mystery motives matter a lot. So what are the motives of a beautiful but injured soldier who, thanks to special relativity, is 20 years younger than her lawyer husband? Or the manipulative dead woman whose mind was superimposed on another woman's wiped brain? Who is on this cruise ship?

Since the book is layers of surprises, I find it a bit hard to write a review without spoilers. So I'll cut to the chase and say that the book is fun, but not bubble-gum--you need to pay attention.

You always do with Gene Wolfe's books. I got stuck in There Are Doors (I suppose I should start it again), but I've liked all the rest I've read. He stretches your mind a little, and there are often things you only notice on re-reading.

UPDATE: Yes, after I slept on it I recalled two more points that hadn't been explicitly solved, and which change the nature of the ending somewhat.