I always find Wyndham enjoyable, but to me this doesn't have the sheer genius of The Chrysalids or the warmth and humanity of Chocky. That being said, it's still a thought provoking read, although one hampered I think by structure. The story is very much in two parts, and the first (and larger) is the less interesting. It's the Children themselves that should be the focus of the entire book, not just of the second half of it. Restricting the narrative in this way means the threat takes too long to get started and is over too quickly.