Very informative. It explains the scientific discoveries and challenges, how they needed to use almost microscopic tools to work with the microgram amounts of plutonium for the first time, how they assembled the Manhattan project, and the different approaches they tried for both enriching uranium and for assembling the sub-critical pieces of uranium into a super-critical piece at the moment of the explosion.

It was also very sad. They intentionally left Einstein out of the work because they knew he was a pacifist. They suspected Oppenheimer of being a traitor the entire time he built the atom bomb, and had agents following him constantly. There were people who wanted to use the atomic bomb as only a show of force, without harming anybody, but they didn't know how to make any such show convincing. They dropped a bomb out of a single airplane on Hiroshima that killed about 60,000 of the 350,000 people there and destroyed 70,000 of the 76,000 buildings in the city -- within about 2 seconds.