Atenție: urmează detalii despre narațiune și/sau deznodământ.
În anul 1858 tânăra Bernadette Soubirous, în vârstă de 14 ani, trăiește cu familia ei în condiții de sărăcie la Lourdes în Franța. Ea suferă de astm și are dificultăți școlare, motiv pentru care este umilită de dascăl. That afternoon, while fetching firewood with her sister Marie and a friend, Bernadette waits for them. Distracted by a strange breeze and a change in the light, Bernadette sees a beautiful lady clad in white, standing on a rock niche. Bernadette tells her companions what she saw, and they promise not to tell anyone else. However, Marie tells their mother when they return home, and the story soon spreads all over Lourdes.
Many, including Bernadette's Aunt Bernarde, are convinced of her sincerity, standing up for her against her disbelieving parents. Bernadette, continues to repeatedly visit the grotto as requested by the lady, accompanied by other citizens of Lourdes. While Abbé Dominique Peyramale refuses to get involved; civil authorities threateningly interrogate Bernadette, but she confounds them with her simplicity and stands behind her story. On one visit, the lady asks Bernadette to drink and wash at a seemingly nonexistent spring. Bernadette obediently digs a hole in the ground and smears her face with dirt. Though she is initially ridiculed, water later begins to flow, which exhibits miraculous healing properties; and ailing people soon begin flocking to Lourdes.