In 1939, Nazi Germany weaves its web, and the old continent plunges into war. At the same time, physicist Albert Einstein is concerned about the scientific advancements taking place in Europe. Soon, both the French and Germans will unlock the secret of nuclear energy. In France, research is being conducted under the guidance of Irène Curie and Frédéric Joliot-Curie. Starting in October 1939, they conduct their work under the newly created CNRS. A frantic race against time ensues, involving scientists, politicians, and secret services, to obtain a rare substance essential for their research: heavy water.