It was a dense, incredibly interesting and engrossing book as titled. It started with a gripping account of Leo Szilard's realization of how a bomb of incredible power could be realized from nuclear fission.
The stoplight changed to green. Szilard stepped off the curb. As he crossed the street time cracked open before him and he saw a way to the future, death into the world and all our woe, the shape of things to come.
I remembered it was such a "good read" that I just finished rereading it. I'm glad I did as I realized that my memory of reading the book was a jumble of a few books from the "Sloan Technology Series". Although Amazon was founded in 1994, this was back before I found it and used the bibliographies from good books to find other good reads. This lead me to a number of great books from the sloan technology series... "The Invention that Changed the World", "Crystal Fire", "The Tube", "Dream Reaper", "Insisting on the Impossible" and "The One Best Way".
I seemed to have lost track of the series and just realized it is still going strong at sloan.org. I recommend perusing it for a number of good reads.
By the way, I also recommend "The General and the Genius" for a more balanced understanding of the Manhattan Project. General Leslie R. Groves was an equally important figure in creating and driving that program...