Alfred Lee Loomis was a brilliant and eccentric financier turned amateur physicist who, in 1926, purchased a medieval stone mansion and transformed it into a deluxe state-of-the-art laboratory. There, throughout the 1930s, he gathered around him many of the greatest and most visionary minds of twentieth-century science--Einstein, Bohr, Fermi, Lawrence, Compton, Bush--men on the brink of greatness whose pathbreaking ideas and research at this scientific Valhalla made it possible for the Allies to win World War II. Loomis's world was a colorful, exciting environment filled with intrigue and scandal. Dedicated to serious science, it also was an ideal venue for networking among scientists, industrialists, and government officials as well as for sexual liaisons, which added to the mystery and allure of Tuxedo Park sojourns. It is impossible to exaggerate the contributions Loomis and his band of scientists made to the war effort: building the radars that provided the means to victory and paving the way for the Manhattan Project and atomic bomb. Jennet Conant brilliantly captures this social scene, and the cutting-edge science that made Tuxedo Park the world's most important scientific playground.