As part of the Physics 2010 decadal survey project, the National Research Council was asked by the Department of Energy and the National Science Foundation to recommend priorities for the U.S. particle physics program for the next 15 years. The challenge faced in this study was to identify a compelling leadership role for the United States in elementary particle physics given the global nature of the field and the current lack of a long-term and distinguishing strategic focus. ''Revealing the Hidden Nature of Space and Time'' provides an assessment of the scientific challenges in particle physics, including the key questions and experimental opportunities, the current status of the U.S. program and the strategic framework in which it sits and a set of strategic principles and recommendations to sustain a competitive and globally relevant U.S. particle physics program.