In 1858, in the Jewish quarter of Bologna, the Pope's soldiers burst into the home of the Mortara family. By order of the cardinal, they have come to take Edgardo, their seven-year-old son. The child had been secretly baptized by his nurse as a baby, and the papal law is unquestionable: he must receive a Catholic education. Supported by public opinion and the international Jewish community, the Mortaras' struggle to get their son back quickly takes on a political dimension. But the Church and the Pope will not agree to return the child to consolidate an increasingly wavering power...