In this moving depiction of a pilgrimage to Lourdes, the master French realist has created a novel of vivid characters and subtle commentary on suffering and the belief in miracles as the last desperate refuge from pain. Based on his own trip to the fabled grotto, the novel follows a simple five-part structure corresponding to the five-day train trip from Paris to Lourdes and back. Zola's brilliant observational powers are at their best as he moves from character to character describing in great detail the physical effects of their illnesses, their hopes, beliefs, fears, and above all endurance. The great novelist himself makes a brief appearance in the story, disguised as a skeptical reporter whose probing questions embarrass a doctor in charge of verifying the alleged miracles. In the end, amidst the tumult of emotions whipped up by religious fervor a miracle of a sort does take place, a psychosomatic cure of a woman suffering from hysterical paralysis. To a few skeptical observers in the entourage the event is a predictable natural occurrence, but to the majority of simple believers it is proof of divine intervention. In our age of televangelists and faith healers, this story has lost none of its relevance.

He was growing excited, full of anguish, and superb. It was his bereavement, his heart wound, which thus exasperated him, the great blow which had felled him for a moment, but against which he again rose erect, defying grief, and stubborn in his stoic belief in an omnipotent God, who was the master of mankind, and reserved felicity to those whom He selected. Again, however, he made an effort to calm himself, and resumed in a more gentle voice#58; "At all events the fold is always open, my dear son, and here you are back in it since you have repented. You cannot imagine how happy it makes me."

Then the Chief of the Detective Force told the whole story: how Detective Mondesir, on being warned by a secret agent that the Anarchist Salvat was in a tavern at Montmartre, had reached it just as the bird had flown; then how chance had again set him in presence of Salvat at a hundred paces or so from the tavern, the rascal having foolishly loitered there to watch the establishment; and afterwards how Salvat had been stealthily shadowed in the hope that they might catch him in his hiding-place with his accomplices.