Here's a perfect example of the all-too familiar phenomenon in science fiction; a writer comes up with a great and interesting concept, but has no idea how to translate into an interesting story. Greg Bear's idea of creating lymphocytes who have become sentient and evolved a human level of intelligence sounded great to me. Such an idea would have some many ramifications and would force us to reevaluate our place in the universe. Unfortunately, Bear hardly explores the wide scope of changes such an event would entail. The world does change, of course, but I just couldn't find any real tension in the transformations wrought by this evolutionary leap, and, even if I was able to care about the two-dimensional characters, they never seemed to be any danger but that of having to to become something bigger than themselves and the threat of a new and bizarre topography. There were several story lines and characters whose purpose seemed to be to fill pages to lengthen this novel. Still, there are moments when Bear discusses the lymphocytes themselves and I felt the book was about to turn a corner an become deeply interesting. Unfortunately, he never managed to find an interesting story line within the intriguing conceptual framework that he explores.