This book is an intertwined story set in Discworld and Roundworld (our earth) but not only is it intertwined with the two worlds, but also between fiction and reality. The story of the Wizards and their struggle to encourage Charles Darwin to write and publish ‘On the Origin of Species’ and to prevent the billions of other possible courses of history is combined with excellent, clear, factual sections on science, mathematics and even society.

I don’t think the story was up to the usual standard of Terry Pratchett’s Discworld books, however the factual parts of the book make up for that and would make for a good read on their own however they are definitely enhanced by the strange fictional world of the wizards especially such things as the god of evolution with his wheeled elephants and turtles.

I want to read this book as part of my goal to start an open source project.