At the time that young Roch is leaving his town of Montpellier with the pilgrim's staff in his hand at Sienna, in Italy, a young woman of 20 is beginning to be talked about. Catherine is the 23rd child of a comfortable artisan's family, the Benincasa. She has just spent three years in retreat and in total silence. As a third order Dominican, she arrived at the height of a life of union with God. And she assembles around her people of every condition who are attracted by her sanctity, and also by her intelligence, her joy and her warm affection. This group is called the "Circle of Fontebranda", from the name of the area where she lived. In the beginning, her action consists of giving advice, guiding Christians of good will in their personal conversion. Then people come to ask her to intervene in the conflicts that are dividing the great families of Sienna.

Catherine, who is not yet 25 years old, succeeds in reconciling the worst enemies. Even the towns of Pisa and Luca come to ask for mediation. This is how Catherine is introduced into the world of politics. But for her, the number on concern is the "illnesses" that the Church is afflicted with: the love of money of those with responsibility, the clergy's neglect, the inertia...

Soon she understands that the "head" must give the example of conversion to a more evangelical life. In 1376, the young woman for Sienna passes through the gates of Avignon.. In spite of the mockeries of the pontifical court whose practices she fearlessly denounces, she succeeds in bringing Gregory XI back to Rome. But, at the death of the Pope in 1378, his successor, Urban VI, takes some actions that irritate the French Cardinals. The latter retort by electing another pope: It's the beginning of the great schism which is going to last 40 years.

They are times of profound suffering for Catherine, who will not cease from upholding Urban VI. She leaves for Rome, and her last months are going to be divided between interior anguish and a correspondence with all the princes of the period, to try to restore peace and unity to the Church. She also dictates the story of her spiritual experience in the book "Dialog". She dies 4 months before Roch, surrounded by her followers. She is only 33 years old.

In a period when the Church, at the top, was no longer living according to the gospel, Catherine of Sienna is the living symbol of sanctity. For, if Christians can be faithful, the Spirit is also faithful and doesn't cease from animating the Church.