This fascinating biography relates the life and times of Irène Joliot-Curie, the eldest daughter of Marie and Pierre Curie. Although less well known than her parents, Irene and her husband, Frédéric, made a contribution to nuclear physics that was of equally ground-breaking significance. And like her parents, they were awarded a Nobel Prize. In 1934, Irène and her husband announced in a report to the French Academy of Sciences that they had created a radioactive atom which did not exist in nature. The bombardment of a simple sheet of aluminum with alpha rays had produced a phosphorus isotope which disintegrated just like natural radioactive elements. Until then radioactivity had been a phenomenon which scientists could not influence or manipulate, but which they were able to observe in certain heavy nuclei. The discovery of the Joliot-Curies marked the beginning of a new era in the relationship of man towards matter: it had become possible to artificially create new atoms and new sources of radioactive radiation. The discovery of artificial radioactivity was also an important step towards the discovery of nuclear fission, made in 1938, and the development of the atomic bomb, completed in 1944. The film makes use of the Curie family photos and home movies, as well as interviews, stock footage, and dramatizations.