Bernard Guillaumet, a non-Christian French journalist, is assigned the job of reporting on Lourdes in the 1990s.
Just before he leaves, Bernard finds out that his wife Nathalie is pregnant. However, he is not told that this pregnancy could put her life at risk.
While researching his report, Bernard comes across the pages of an old family manuscript.
The manuscript was written by his ancestor, Henri Guillaumet, a positivist scientist who met Bernadette at Lourdes in 1858, a meeting which profoundly affected Henri and forced him to reconsider the miracles performed following the apparitions of the Madonna of Lourdes. One of the most important miracles Guillaumet had to reconsider was the healing of his wife Claire, who had been on her death bed as a result of tuberculosis, and was completely restored by the miraculous waters of the grotto in which Bernadette saw the Immaculate Conception.
The film uses the pages of the manuscript to trace the lives of Bernadette, Henry and Bernard, three characters who come together before pursuing parallel journeys according to a Providential design.