Tourists are a most common sight at the abbey of Mont Sainte-Odile in the summer. So, when a tall, somewhat hefty man walked down the marble stairs leading to the first floor of the guesthouse, hardly anyone noticed. His backpack contained a Bible, which is normal in a place where people come for religious pilgrimages, but this Bible was more than 500 years old. Along with it, the man carried a 15th-century incunabulum, works by Cicero and the eighth-century theologian Alcuin, and three more dusty, priceless books.

He'd gotten them from the abbey library. The door had been open, and he'd slipped right in. He picked six books from one of the oak bookcases standing against the walls, and walked right out through the Saint-Pierre chapel, briefly glancing at the marble tomb of Saint Odile — the revered saint who founded this mountaintop abbey in the seventh century — on his way out.

Now, the square-jawed, long-legged man sauntered through a swarm of tourists near the parapet enclosing the religious site. It was a warm, sunny day in August, 2000, and he had just stolen from one of the holiest sites in Alsace, a historical region in northeastern France. On countless occasions, he had soaked up the views of the hillsides, blanketed with pines, and the sprawling Rhine Valley. He made himself a promise not to steal from the library anymore, he would later tell police investigators. Then he strolled by the church Notre-Dame de l'Assomption and, walking under the entrance porch, left the site.

When Véronique Buntz, a housekeeper, entered the library a few days later and set about dusting the bookcases, as she had every Friday since her first day at Mont Sainte-Odile, over a decade earlier, she knew something was amiss.

Of the site's myriad rooms, the library was the one where Buntz, a blue-eyed woman with natural gray hair even in her 30s, felt most at peace. A small, vaulted room, it had once been known as Calvary, a place where canons and nuns meditated on the Passion of Christ. In the mid-19th century, a canon turned it into a library, amassing more than 3,000 books donated by seminaries and monasteries from the region.

In the 1990s, an amateur historian started drawing an inventory and had found ancient editions of works by Aristotle, Homer, and the Roman playwright Terence. Especially valuable were 10 incunabula — rare books printed before 1501, during the earliest years of the printing press. Sermons by Augustine, bound in sow skin, from 1489. Three Latin Bibles, printed in Basel and Strasbourg. Works by the Roman poet Virgil, printed in 1492 in Nuremberg. A Bible commentary by Peter Lombard, a 12th-century Italian scholar.

Now one was missing. On the lower shelf where they were supposed to line up, there was an empty space.

Buntz scurried out of the room. She bumped into Charles Diss, 61, the director of Mont Sainte-Odile, a short man with an affable face and protruding ears. "I think books in the library are missing," she whispered, as if uttering blasphemy. Diss was rattled. The library was accessible to some of the 60 employees, as well as to groups of 30 worshippers taking turns in adoration of the Eucharist, a tradition going back to the years following World War I.

The Notre-Dame de l'Assomption church next to the hotel at Mont Sainte-Odile | (Benoît Morenne/Courtesy Narratively)

Buntz and Diss drove the weaving road downhill to file a complaint with the local police station. For a moment, they thought that things would be left at that. The door was often left unlocked, after all. It appeared that only one book had been stolen, or simply borrowed by a fervent but dreamy pilgrim, and not returned. No additional security measures were taken.

But when Buntz entered the library one day in November, just a few months later, the remaining incunabula were gone. The empty shelf stared grimly at her like an open wound. The gendarmes began an investigation and soon roamed the area. License plate numbers were noted; tourists spending a night in one of the guesthouse's 110 rooms, scrutinized; personnel, screened. "It was like looking for a needle in a haystack," says Jean-Pierre Schackis, the main investigator on the case, 51 at the time. More than one million people visit Mont Sainte-Odile every year, and the surveillance cameras at the site entrance didn't even work properly.

A few days prior, the cameras had stared blankly at a white Citroën parking late in the evening, and at the 6 foot 2 inch man who had come out of it. He had walked back to the car two hours later, carrying two bags full of nine heavy incunabula, according to previously undisclosed police records.

The lock on the library door was replaced with a sturdier one, and access to the room restricted. For months, there was no further pilfering. It was a relief. The thief hadn't been caught, but at least the books would stay where they belonged. Life continued. In the fall of 2001, Diss, the head of the site for 23 years, was succeeded by Alain Donius, a bespectacled, disheveled priest of 51. No one told him about the thefts. The matter was considered closed.

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