This book depicts the life of the Austrian physicist Marietta Blau (1894-1970). She was considered extraordinarily gifted by Albert Einstein and was nominated three times for the Nobel Prize in Physics, twice by Erwin Schrodinger. On the other hand, no obituary was ever published on her. At the Institut fur Radiumforschung in Vienna, the 'Radium Institute', Marietta Blau developed the photographic method of detecting nuclear particles, a method which played a prominent part in nuclear physics in the following decades. By means of this technique new fundamental particles, the pion and the K-meson, were discovered in the 1940s. The biographical part of the book which includes personal recollections by friends, describes Marietta Blau's life in Vienna before 1938, her emigration to Mexico, her move to the USA in 1944, her work at leading research centers in the US, her return to Vienna in 1960, and the last decade of her life in her hometown, where she continued to work at the Radium Institute for four years. One article is dedicated to her scientific work. Her pre-war research culminated in the discovery of 'disintegration stars', which consist of the tracks of nuclei or nuclear fragments on photographic plates, and made visible for the first time the reactions of atomic nuclei with particles of cosmic radiation. A bibliography of Marietta Blau's scientific publications as well as references to selected literature are also included. Brigitte Strohmaier, born in Vienna in 1948, teaches at the Institut fur Isotopenforschung und Kernphysik of the University of Vienna (formerly Institut fur Radiumforschung of the Austrian Academy of Sciences).