The biography of Rosalyn Yalow, as told by her longtime friend and colleague Eugene Straus, is the story of a woman who prevailed against class and gender prejudice to reach the pinnacle of the science world. Yalow's story is related against the backdrop of her later years, when, after having won the Nobel Prize in medicine for inventing a revolutionary test for certain kinds of hormones, she was suddenly felled by a stroke and brought to a hospital where, unrecognized, she was dumped" as a charity case onto another hospital. Straus's account of Yalow's slow but ultimate triumph over crippling illness is of a piece with that of the dazzlingly talented and tenacious young woman who, despite the barriers placed before her by a male-dominated medical establishment, never compromised her principles of hard work and scientific integrity.