Yum. Devoured the 3 parts of this and would happily have read a dozen more.

The first story was probably the best, and I noticed again, as I did in Gradisil, how Roberts can somehow make complicated and unlikely technology seem somehow simple and natural, in a plausible way.

Middle story was excellent, and fooled me again and again. And the little interlude in the mind of the sister was also great. Last seemed weaker, but no complaints.

Beyond the basic mystery stories, and the SF, and the socological themes, there's a level where this book is playing with its reader, letting them guess at some things, and then foooling them again and again. As a good mystery story does. But also telling the reader what it's doing, right in the preface, and still fooling them. Genious.