A truly charming science fiction series for kids from a highly intelligent author, the best friend of another great-J.R.R Tolkien. This book is particularly the highlight of the series as it is well-written and enjoyable for all ages. Written in a unique order, some of the other books are so multi-layered it can be confusing to some but if you stick it out and read the whole series, it's a delightful experience at any age.