Tomorrow and Tomorrow begins a hundred years after the Hiroshima A-blast. We meet Joseph Breden, a nuclear physicist chosen as one of the guardians at Uranium Pile Number One. As a member of the Global Peace Commission regulating atomic power, Breden knows his job is vital. But he is troubled with dream - horrifying dreams which suggest he overthrow his duties and permit an explosion! He recognizes a psychological breakdown. But why? Was he driving himself to destruction? Or someone else?