The book explores the myth of Eden and religious "paradise" and how it has shaped the world as we know it. From Pythagoras and his ideas of attaining paradise on earth via harmony, to Columbus discovering America and believing he had found Eden. From Samuel Hartlib trying to create his version of a Utopia in Britain, to Omar Khayyam and his ideas around mathematics and social conditions. From apocalyptic Catholicism of the 15th century, to Social Darwinism and the Nazi's final solution.
It isn't a heavy read; although the title might make it sound like it is. The subject matter is introduced, explained and then related to the next topic in a style that flows well, reads well and allows you to take in what Rushby is saying without being patronising nor too complex.
The biggest flaw in this book is actually his little anecdotes of his granddad/time in Asia etc. It just never really fits with the rest of the book (read: not all that interesting). But the rest of it is great.
It's not too long (about 250 pages) and is interesting and informative. I don't normally read all that much non-fiction, but found this a breeze.