Drawing on unmined archives and original interviews, Rebecca Lubot tells the story of how US lawmakers grappled with issues over presidential succession and inability and vice-presidential vacancy and ultimately ratified the Twenty-Fifth Amendment. She argues that nuclear anxiety played a crucial role in the development of the amendment and its aftereffects, showing how politics and culture reflected this anxiety, and multiple administrations intensified it. She also offers solutions to the amendment's gaps. As the threat of accident, miscalculation, or madness looms, never has a book on the intersection of presidential continuity and the nuclear age been more necessary.