You can tell a lot about people by what they do on the subway.

In the early hours of a weekday morning, heading to work, we are transients. We have no home but that subway car. For a few minutes, we are co-habitants: neighbors, bound by time and space and dirty plastic seats, blinking at one another as the lights flicker, the windows rattle, and the stops go hurtling by in a blizzard of white tile.

I'm taking the train earlier these days; I usually step onto the subway platform around 7:30. It's easier to get a seat on the local. But sometimes I'll take the express, and stand, and spend a few moments struggling to stay awake. It's interesting to see what people are doing at that hour.

A lot of people do the Sudoku puzzle these days. A few still struggle with the crossword. Some take the Times, and fold it into long rectangles for easy reading (a peculiar New York form of origami, I think.) Increasingly, people are reading a Kindle or Nook. Some are clutching paperbacks by Grisham or King or Steele. Once in a while, a young man with a yarmulke, dressed in black, will step onto the train and crack open a book of Hebrew. Sometimes, I'll see older ladies with little pamphlets, reading lessons from the Bible.

But the other day, while I was unfolding my New York Post—there's a confession for you!—I caught sight of a very serious young woman seated across from me, hands folded, eyes closed. Her lips moved. And as I looked down at her hands, I noticed they were fingering beads.

She was praying the rosary.

I've seen that before; like that folded New York Times, it's a peculiar New York phenomenon, a prayerful habit that suggests that we are a distinctly devout city, full of immigrants and varied cultures that are constantly rubbing up against each other and giving people a lot of reasons to pray. But this morning, I found it unexpectedly moving. This young woman was in prayer. But a special, profoundly personal kind of prayer.

Pray for us sinners, now and a t the hour of our death, Amen.

In a hole in the ground, clattering under a river, surrounded by darkness and strangers, one of the anonymous throng that had been herded into a tin box was praying to a woman full of grace.

Subways are a mystery—they shouldn't work, but they do, and it's a minor miracle we aren't swallowed alive by the earth. But that morning, one of our neighbors on the subway—a traveler on this journey, a fellow transient, a pilgrim bound for points unknown—was embracing another mystery. She was holding it in her hands.

As I thought about that, and looked around the subway car, I understood that we had become a kind of church, each of us deep into our own silent prayers of Sudoku or Cindy Adams or Thomas Friedman.

Or Mary.

During this month devoted to her, at churches around the globe, there will be processions and crownings, hymns and devotions. My own parish in Queens likes to stage a "living rosary" every May, with sixty people outside the church, each representing a bead, saying aloud that ancient prayer of the church that continues to offer so many solace and inspiration and peace.

But on any given day, you don't have to look far to see that prayer come alive. Any subway car will do.

I looked again at the woman with the rosary and saw her smile to herself. And I smiled, too.

A subway car of strangers was no longer full of people.

To those who choose to believe, it was full of grace.