Dry and with more of the science than I expected, I found this book fascinating and gripping. The first half of the book traces the 20th century history of nuclear science into the second world war and the key scientists themselves. The second half is the recognition of the bomb as a possibility leading into the production and use of nuclear weaponry, with more focus on the politics and administration of the Manhattan Project.  

Trigger warning for the use of many quotes using slurs for the Japanese, presented without warning or comment. The book also contains fairly gruesome accounts of the aftermath of both the nuclear bombs and firebombings.