After he was arrested, according to the childhood friend, Gabriele's wife asked what he thought would happen now that he'd been accused of betraying the Holy See. "I started out scrubbing toilets," he told her, "and I'll probably go back to scrubbing toilets." He told Nuzzi, "My conscience is clear."

So he went to Vatican jail to do his time. His wife came to see him once a week, and he was allowed out for Mass in a small chapel on Sundays. He passed his days by painting, and he joked to Manuela that maybe he'd hold an exhibition of his canvases when he was released. "But they're all so dark," she told him, "like Munch."

The narrow legal machinations might have been eminently fair, but in a broader sense Gabriele's motives do matter. Rightly or wrongly, he believed he was exposing misbehavior in his beloved Church, willingly risking his cherished career and his family's security. "So who's the bad guy?" Nuzzi asks. "Is it the butler? Or is it the guys in all these documents?"

He feels terrible for Gabriele. Nuzzi told him there were risks, but he never expected his source would be arrested, would be sent to Vatican jail. "He can't spend Christmas in there," he told me in early December.

In the end, though, Gabriele will be a footnote to his own story, because it's not about him anymore. In fact, on the first Sunday in June, the Italian paper La Repubblica published leaked Vatican documents it reported had been delivered after Gabriele had been arrested—along with a note that claimed the butler was merely a scapegoat.

"It's a story now," Nuzzi says, "of, for the first time, this wall of silence that's always been protected and has now been pierced. And that sets a precedent."

Though Pope Benedict's retirement was startling—he was, after all, the first pope to retire in six centuries—it almost certainly was not because of the leak scandal. He is old and ill and never really enjoyed the public pomp of being pope anyway; retiring, rather than lingering and deteriorating, was not unreasonable.

But the Vatican is more than the pope, and for the greater institution the leaks were never primarily about the betrayal of Benedict. The scandal was always about a breach in the cloistered secrecy of a tiny sovereign nation. The palace gossip and the allegations of corruption that seeped out were merely evidence of a larger, more fundamental problem, much like rivulets of water trickling from the face of a dam about to burst. No matter who is elected pope this spring—a reformer from the Southern Hemisphere, an Italian traditionalist, a Filipino!—the institutional Vatican will surely spackle the cracks. The Vatican's business is not to be shared.

It's a curious perspective. In early December, when one of his sources was doing time in Vatican jail, Nuzzi tried to explain it. He told me a story, in the same way that he'd been told, about an elderly monsignor who lived in the Vatican not so many years ago.

One warm night, when the monsignor had guests for dinner and the window open to catch the breeze, the cats that prowl the tiled roofs were making a racket, howling and mewling in the twilight. The monsignor despised those cats. So he got up from the table, retrieved an antique carbine, and fired a few shots out the window. Then he sat back down as if nothing unusual had occurred.

The next morning, two nuns climbed to the roofs with buckets, into which they deposited a few dead cats. And nothing more was ever said about the incident.

The point, Nuzzi said, the key to understanding everything else, was what never happened: No one suggested taking away the monsignor's rifle. The real problem was what was left littering the rooftops. And so it was enough, it was proper, to simply cart away the bodies.

"Gabriele told me that story," he said. "I think Gabriele told me." He shrugged. "You can say Gabriele told me. It was one of them."

The pope pardoned Gabriele three days before Christmas and expelled him from the Vatican for eternity.

† On May 25, Vatican police also arrested Claudio Sciarpelletti, a 48-year-old computer technician in the Secretariat of State, after they found a sealed envelope in his desk drawer with "P. Gabriele" written on it. The documents inside—mostly letters and e-mails—weren't of any interest. Sciarpelletti initially gave investigators three different explanations as to how the envelope got into his desk. At his trial in November, Sciarpelletti testified he simply couldn't remember how he'd gotten it or why. He was convicted of obstruction of justice, though his role apparently was so minor he received only a two-month suspended sentence.