In the fall of 1940, as German bombers flew over London and with America not yet at war, a small team of British scientists on orders from Winston Churchill carried out a daring trans-atlantic mission. The British unveiled their most valuable military secret in a clandestine meeting with American nuclear physicists at the Tuxedo Park mansion of a mysterious Wall Street tycoon, Alfred Lee Loomis. Powerful, handsome, and enormously wealthy, Loomis had for years led a double life, spending his days brokering huge deals and his weekends working with the world's leading scientists in his deluxe private laboratory that was hidden in a massive stone castle. In this dramatic account of a hitherto unexplored but crucial story of the war, Jennet Conant traces one of the world's most extraordinary careers and scientific enterprises. She describes Loomis' phenomenal rise to become one of the Wall Street legends of the go-go twenties. He foresaw the stock market crash of 1929 in time to protect his vast holdings, making a fortune while other bankers were losing their shirts. He rode out the Depression years in high style, and indulged in the hobbies of the fabulously rich. He raced his own America's Cup yacht against the Vanderbilts and Astors, and purchased Hilton Head Island in South Carolina as his private game reserve. Conant writes about the glamour and privilege of his charmed circle as well as Loomis' marriage to a beautiful but depressive wife, whom he sent away for repeated hospitalizations while he pursued a covert affair with his protégé's young wife. His bitter divorce scandalized New York society and drove Loomis into near seclusion in East Hampton. At the height of his influence on Wall Street, Loomis abruptly retired and devoted himself purely to science. He turned his Tuxedo Park laboratory into the meeting place for the most visionary minds of the twentieth century: Albert Einstein, Werner Heisenberg, James Franck, Niels Bohr, and Enrico