Raised in Australia, Helen Caldicott trained as a physician and devoted herself to the treatment of children afflicted with cystic fibrosis. But it was in the political turmoil of the 1970s and 1980s that she found her true calling. Resigning from the faculty of Harvard Medical School, she helped to found and was the first president of the Physicians for Social Responsibility (PSR) and the Women's Action for Nuclear Disarmament (WAND), two organizations at the forefront of the nuclear-freeze movement. Over the next ten years Caldicott brought her message to world leaders, to the media, and to audiences of thousands whom she roused to action with singular eloquence. In 1985, PSR's umbrella affiliate, the International Physicians for the Prevention of Nuclear War, was the recipient of the Nobel Peace Prize. . Physician, wife, and mother of three, Caldicott found that success as an activist did not come without cost. She reflects on the adverse impact her political work, with its constant traveling, had on her family, her medical career, and her personal well-being.