Nicolas Wild travels to Iran at the invitation of his friend Sophia, daughter of the well-known humanist Cyrus Yazdani, who had been assassinated in mysterious circumstances. Here, Wild discovers Zoroastrianism, one of the world's first monotheistic religions and an inspiration to numerous philosophers, among them Nietzsche. As he meets and talks to people in Iran, Wild becomes immersed in Cyrus's story. With Sophia's permission, he goes to Geneva to hear the testimonies of the assassination trial at the Criminal Court. Inspired by the life of a real-life activist, Wild's account reveals more than the story of one man's life or a court case. With characteristic humour - both unprejudiced and warm - he portrays a complex picture of a people and a culture.