During a visit to her birthplace, Mafalda, the third daughter of the juggler Orontius, finds an ancient coin in the ruins of a chapel where Saint Catherine was celebrated in 1551. The coin shows the profile of a head that resembles hers in every detail. Full of curiosity as to who this woman from the distant past was, she and a childhood friend set off for Egypt and St Catherine's Monastery. This is the beginning of an exciting journey full of historical events, love and Mafalda's spiritual insights as she searches for her identity.