This is highly readable book details the development of the first atomic weapons -arguably humankind’s darkest hour. It is a thoroughly researched account which plays out against the chronological back drop of the Second World War.It is populated by a cast of some of the world’s greatest physicists and most notorious World leaders.Throw into the mix espionage and a plethora of spies and you have a nonfiction narrative more compelling than any Le Carre novel. Not only are the events clearly detailed but they are supported by intriguing footnotes that appeal equally to the reader of popular science and that of history. Indeed the text is a pleasing blend of science and history, discussing the discovery of fission and enrichment as well as the Allies campaign in Italy.An excellent appendix also includes a useful list of the main protagonists and a chronology of events as they played out from a British, US and Russian perspective. Post war events in Czechoslovakia, the Blockade of Berlin and the emergence of NATO have a chilling current relevance in the context of Ukraine. An intriguing theme throughout the depiction of events is the relationship between science and morality. Why was German atomic technology so behind that of America and Britain? Did brilliant physicists such as Heisenberg deliberately undermine the National Socialist Programme? Did the bombing of Hiroshima and Nagasaki end the war earlier thus saving more lives than were lost in the two bombings?