In the autumn of 1950 an Italian physicist and pupil of Enrico Fermi, Bruno Pontecorvo (1913-1993), left for Dubna, Russia and a new life. Pontecorvo only returned to Italy 28 years later, for Edoardo Amaldi’s 70th birthday celebrations. He visited Italy several times after that, but he never changed his mind about living in Russia, where he died in 1993. This documentary recounts the life of this physicist, one of the sharpest minds of his times, through the events that shaped his choices and his most important scientific contributions. The film is full of quotes from his autobiography and recollections by colleagues, Italian and foreign friends and family (including his brother Gillo, a famous film director). Born in Pisa, he received his physics degree in Rome while a member of Enrico Fermi’s illustrious group working on research into slow neutrons, which would earn Fermi the Nobel Prize. From 1936 to 1940 he spent one of the most brilliant periods of his life in France, on a scholarship from the Ministry of Public Education, and among those he forged friendships with during that period was his second great mentor, Frédéric Joliot. In 1940 France fell under German occupation and Pontecorvo, of Jewish origin, was forced to flee with his family through Spain and Portugal, then on to New York and finally Canada. He then left for Dubna, where he discovered neutral p-mesons and studied their generation out of collisions between neutrons and protons and collisions between neutrons and various atomic nuclei. For his work in this area he won the National Prize in 1953. Pontecorvo received many prizes and awards, but never the Nobel. He is the source of many brilliant ideas, including neutrino oscillations, which inspired many research teams in Italy and elsewhere and led to the awarding of three Nobel Prizes.