He hiked up the steps of the Basilica and slipped into the portico. Five doors led into the nave. All were sealed except for the one at the far left, the Door of Death. In the opening stood Father Jacobo, an emaciated-looking Mexican cleric with strawlike gray hair. He stepped aside so Moretti could enter, then closed the door and lowered the heavy bar. “I’ll come back at seven to let in your men,” the priest said. “Be careful up there, Niccolo. You’re not as young as you used to be.”

The priest withdrew. Moretti dipped his fingers in holy water and made the sign of the cross before setting out up the center of the vast nave. Where others might have paused to gaze in awe, Moretti forged on with the familiarity of a man entering his own home. As chief of the sampietrini, the official caretakers of the Basilica, he had been coming to St. Peter’s six mornings a week for the past twenty-seven years. It was because of Moretti and his men that the Basilica glowed with heaven’s light while the other great churches of Europe seemed forever shrouded in darkness. Moretti considered himself not only a servant of the papacy but a partner in the enterprise. The popes were entrusted with the care of one billion Roman Catholic souls, but it was Niccolo Moretti who looked after the mighty Basilica that symbolized their earthly power. He knew every square inch of the building, from the peak of Michelangelo’s dome to the depths of the crypt-all forty-four altars, twenty-seven chapels, eight hundred columns, four hundred statues, and three hundred windows. He knew where it was cracked and where it leaked. He knew when it was feeling well and when it was in pain. The Basilica, when it spoke, whispered into the ear of Niccolo Moretti.

St. Peter’s had a way of shrinking mere mortals, and Moretti, as he made his way toward the Papal Altar in the gray coat of his uniform, looked remarkably like a thimble come to life.