When Fiver senses that a great danger is coming to the warren, only his brother and a few others believe him. Unable to convince the other rabbits, this small band leaves on a journey in search of safety that takes them through farmyards, across roads and rivers, and into warrens with very different cultures. 
 This is an absolutely fantastic book. The adventure story alone is well worth the read, but the amateur mythicist in me was especially impressed with the construction of an entire rabbit culture and religious system, language included. Especially impressive is how familiar and, yet, distinctly alien the rabbit culture is. This rarely felt like a book about people that happens to be set in a rabbit setting. Rather, this was a book about rabbits, only slightly anthropomorphism. The characters and their culture retain a great deal of what can only be called 'rabbitiness.' 
 Most books get at least one aspect right. Some get a few things right. When this happens, the book may be called masterful, or great. But Watership Down is one of the very few books that tempt me to use the word 'perfection.' This is a masterpiece and I think that anyone who hasn't read it yet is somewhat impoverished. There's something about it that just touches the Jungian collective subconscious. This is the hero with a thousand faces pulled off in a way that feels natural. 
 Though marketed as a children's book (although perhaps a little too gruesome/frightening for younger kids), Watership Down is a must read for adults as well.