In the 1850s, the French railways sold a special ticket for one tiny farming village: an eight day return. Not because the village was far away. Because the queue you were travelling to join could take you three days to get through. It was the queue for one confessional, and for the priest inside it, who had a habit of telling total strangers exactly what they had done.

His name was John Vianney, and nothing about him promised marvels. He was a farm boy who nearly failed out of seminary because his Latin was too weak, and in 1818 he was sent to Ars, a village of two hundred souls, precisely because it was considered too small for him to do much damage. He stayed forty years. And somewhere in those first years, the reports began. A stranger would kneel at the grille, begin a careful, edited confession, and the little priest on the other side would quietly finish it for them: the sin they had left out, the year it happened, the person it involved, the thing they had told no living soul. Hundreds of such accounts were later sworn under oath in the Church's formal investigations. The pattern in them is always the same. He did not accuse. He simply knew.

Word spread the way that kind of word spreads. By the 1850s more than one hundred thousand pilgrims a year were descending on a village with one street, doctors and duchesses and sceptics in the same line, and the line ran to two and three days. Vianney sat in the box up to sixteen hours a day, summer and winter, an old man living on a few potatoes, while all of France queued to be seen through.

He died in August 1859, worn out at seventy three. In 1904 the body was exhumed and found intact, and it lies today in a glass reliquary above an altar at Ars, where you can stand in front of it. In 1925 Rome canonized him and made him the patron of every parish priest on earth. You are free to reach for explanations: cold reading, gossip networks, the suggestibility of people who had queued for days. The thousands who knelt at that grille swore to something simpler, and stranger. He knew. Witnessed. Subscribe.