Michael Toth points at a computer screen filled with what seems to be a jumble of Arabic and Greek letters.

To get to this jumble, he has traveled from Washington to an isolated, fortress-like monastery in the middle of the Sinai Desert, home to the oldest continuously operating library on the planet.

He has helped assemble a global team of scientists that arrived with cutting-edge technology at this spot, three hours by taxi from the nearest commercial airport.

The image he has paused to appreciate is one of a steady stream coming from the room next door, where a high-definition camera is focused on one of the monastery’s rare and priceless ancient manuscripts. The manuscript rests in a cradle that looks like a chair tilted back at an angle, but with hydraulic lines and strange lights attached.

One more room over, in the makeshift command center, specialists are scrutinizing the day’s results, and the monastery’s head librarian, a wispy gray beard to his stomach, waits in a red velvet chair for the next request to turn a fragile manuscript page.

“This is the first time since the 9th century that anyone has seen this,” Toth says of hints of text below the more visible words. The first time since the era of Viking invasions and Charlemagne.

The more prominent legible words are 1,200 years old and are interesting enough, but they are not what the scientists are here for. The team is really after the overwritten text from centuries earlier, last seen by the person who scraped it away to recycle the precious animal-skin parchment.

Such erased texts are known as palimpsests, and until their pages enter the imaging room, no one alive now or, in many cases for more than a millennium, can say for sure what has been hidden. The work is tedious, like carefully brushing away sand at a traditional archaeology dig, but the promise of what can be found is a powerful motivator.

This is Toth and his colleagues’ most ambitious project to date, and it is just one component of a major transformation under way in the desert. The team is working within the stone walls of the Sacred and Imperial Monastery of the God-Trodden Mount of Sinai — St. Catherine’s for short.

For 17 centuries, the Greek Orthodox Christian monks here have protected an unparalleled trove of manuscripts. Now the monastery is in a multimillion-dollar push to physically and digitally protect its treasures and make them easily accessible, in most cases for the first time, to scholars around the world.

In the process, the monks will establish a model for the preservation of irreplaceable ancient manuscripts in a world where more and more of them are threatened by the chaos of war and revolution. “Working with this stuff is an amazing privilege,” Toth says.

St. Catherine’s head librarian, Father Justin, came to Washington in 2008 to learn whether Toth and his colleagues might be able to offer some help. Father Justin had been working to digitize the monastery’s huge manuscript collection using standard photography for 10 or so years. But the time had come to explore the archaeology of the palimpsest subset of the collection with hidden words standard photography can’t reveal. Toth was managing a group that had made a global name for itself in this sort of imaging detective work, an endeavor he entered by accident.

In 1999, Toth, then a policy director at the National Reconnaissance Office, which designs spy satellites and imaging systems, read in The Washington Post about an interesting project at Baltimore’s Walters Art Museum. An anonymous bidder had paid $2 million at auction for what, on the surface, was a prayer book handwritten in Europe in 1229. But the value came from what the prayers obscured: 10th-century copies of key works by the famed Greek mathematician Archimedes, including the only known copies of some.

Scholars had discovered the hidden text in 1906, but they couldn’t read much of it. After the new owner — still known publicly only as Mr. B — took possession, he agreed to lend the palimpsest to the Walters to try to reveal the rest using advanced imaging techniques.

Toth saw connections between high-tech surveillance imaging and what it was going to take to pull off proper imaging of the palimpsest. On a whim, he e-mailed the museum’s director and offered his services. Soon enough, Toth was volunteering as a project manager, working with Will Noel, a Walters curator overseeing the project, to build the necessary team of scientists.

The 10-year project pushed the limits of existing technologies, photographing pages using special lights and filters in ways that allowed computerized enhancement of the lost text. It was wildly successful, and by eight years in, Toth had retired from the government to pursue this new passion full time. He is now 55.

Techniques the team developed, not only for imaging but also for managing the massive volume of data such work generates, became standards in the field, and the group began receiving requests to take on new projects involving palimpsests or text lost in other ways, such as through water damage.

Toth and the team — all independent specialists — worked with the Library of Congress to reveal hidden aspects of Thomas Jefferson’s copy of the Declaration of Independence, such as the fact that the founding father had erased the word “subjects” and replaced it with “citizens.” As requests for help piled up, they went global, working in Europe and the Middle East.

In every project, Toth and his colleagues handled the technical side: getting the images. Scholars had to do the analyses. And the team was adamant about making the data public to benefit as many people as possible.

By 2008, Father Justin was one of the people looking them up. The challenge he presented would be nothing like any of the group’s previous projects. Besides the difficulty of getting equipment to the desert and obtaining proper approvals, there was the size of the collection. At that point, all told, Toth and team had imaged perhaps a couple of hundred pages. St. Catherine’s had thousands.

Since at least the 4th century, monks have lived in a valley at the base of Mount Horeb, which leads up to what long tradition says is the Mount Sinai of biblical fame. They came to be close to what they believed, and many today believe, is the burning bush from which God spoke to Moses, as described in the Old Testament.

In the 6th century, the Emperor Justinian I called for construction of a monastery at the site. Today, pilgrims and tourists encounter the 60-foot-high fortress walls and basilica built to fulfill his decree. There are plenty of camels, but visitors who expect to see the rolling sand dunes of movie deserts find instead massive granite cliffs.Visitors expecting monks with long beards dressed in black robes rising before dawn to recite ancient prayers, however, find that stereotypical vision completely fulfilled. The monks’ lives resemble those of their forebears closely because they consider preservation of those traditions one of their most sacred charges. They’ve just added a few iPads and PowerBooks to the mix.

Just about everything in this place is of historic interest to someone, from the unparalleled collection of religious icons to the graffiti — crusaders carved their names and coats of arms during visits around the 12th century.

“It’s a very contemplative place,” Toth says. “It’s a place where you gain a new perspective on yourself and on history.”

There is an impressive collection of printed books, but one of the monks’ most recognized successes has been in preserving what many experts consider to be a collection of ancient manuscripts second in significance only to the Vatican’s huge collection in Rome.

Most of the library’s texts are religious, but other writings are here as well, such as a 9th-century copy of Homer’s “Iliad,” complete with grammar and vocabulary notes. “I’ve been fascinated by this,” Father Justin says. “Obviously, someone came here centuries ago and brought his homework with him, and it’s still here.”

For scholars, working with the Vatican’s collection is akin to conducting research at a zoo. Those manuscripts were intentionally gathered, and in most cases they’ve been cleaned, taken apart and rebound. Much can be learned from subjects in captivity, but if the Vatican is the zoo, then working at St. Catherine’s is to venture into the wild — ancient manuscripts in their natural habitat, there in most cases because someone was using them.

“That’s something that is so important about the library,” says Father Justin, a Texan first attracted to Greek Orthodoxy by a love of Byzantine history who joined the monastery in 1996. “Because it was built up by the living community here, it’s still in its original context, and that’s an added dimension to every manuscript.”

The monastery holds at least 130 palimpsests, all from medieval times. One of the richest sources of palimpsests has been a collection known as the New Finds — “new” being a relative term in a place so old.

Across the monastery from the imaging room, there is a small wooden door that could once be reached only by ladder — and few apparently made the climb. Behind that doorway and through two more is a storage space probably untouched from the 18th century until 1975. It was then, while cleaning up damage from a nearby fire, that the monks ended centuries of procrastination and inventoried the nearly forgotten storage area.

The space was miserably dusty, but one monk soldiered on and discovered a lost trove of damaged ancient manuscripts whose significance scholars are still probing.

With the chance to study the monastery’s palimpsests, the experts hope to better understand whether there are discernible patterns in the decisions people made about what texts they scraped away. Sometimes monks brought in parchment that was already scraped; sometimes they did it themselves. Pages might have been chosen because the material on them wasn’t considered important, but selection could just as easily have meant that the monks thought they had enough copies of a particular text.

In some cases, a single manuscript leaf might include three or more layers of text, all from different centuries. And sometimes pages from one scraped manuscript were taken apart and used in multiple other manuscripts, creating puzzles to be pieced back together.

Before this project, only three palimpsests had been studied at St. Catherine’s, and not with advanced imaging. The most famous is called the Syriac Sinaiticus, which two intrepid Scottish sisters uncovered in 1892. The overtext was stories of female saints, but the undertext, some of which they glimpsed by steaming pages apart over a tea kettle, proved to be a late 4th-century copy of the four canonical gospels. It was written in the language Old Syriac and offered scholars new information about what the gospels might have looked like in their original form.

In the 1990s, scholars worked with the only two known manuscripts written in a lost language called Caucasian Albanian, deciphering the language for the first time.

It’s difficult to conceive of a better naturally occurring place than this desert monastery to preserve ancient documents. Mold and insects are the main foes of book preservation, but neither is an issue. Humidity is so low that, despite the summer heat, a culture emerged that still favors long thick robes and head wraps without a heatstroke epidemic. There are months or even years between rainstorms. And in this dry place, there are no rats to chew through pages.

The library’s isolation further aided the documents’ preservation, though it has also severely hampered access. It doesn’t take two weeks by camel to get there anymore, but it’s still a long way to travel for research.

And even under the excellent natural conditions in a place where time seems to have proceeded more slowly, time still leaves unwelcome marks. Ink fades; pages eventually crumble. But technology offers the secret of preserving these manuscripts for centuries to come.

Soon after Father Justin’s fact-finding mission to the Walters Museum, Michael Phelps, founder and executive director of the Early Manuscripts Electronic Library in Los Angeles, signed on to lead the St. Catherine’s palimpsest project, including fundraising. After months of discussing issues such as whether the monastery’s electrical system could support all the needed equipment and whether the project would be too disruptive to the 25 or so monks in residence, Phelps and two Greek colleagues managed to secure approval for a limited test run. It sampled pages from 16 manuscripts and found buried text in nine languages, a Hippocratic medical text 500 years older than anything previously known, and evidence to support new theories about connections between Europe and the Middle East that predated the Crusades.

It was a convincing showing. His Eminence Archbishop Damianos of Sinai was on board. “This is the last frontier in the Sinai library,” he says. “This is the last repository of information that hasn’t been clarified and claimed.”As important in the agreement was the Arcadia Fund, a U.K.-based nonprofit focused on protecting cultural knowledge. In 2010, it agreed to provide $2.1 million for five years of imaging.

Late last year, the team returned to Sinai to begin its work in earnest.

It’s about 8 a.m., and the imaging team is standing in a circle in the command room. They’re not praying, though the timing of this daily ritual is dictated by the monks’ morning prayers. The standing is a management trick Toth advises to keep a group on track. Knowing that you can’t sit until everyone has aired concerns and reported on progress offers a powerful push toward brevity.

At times they cover glitches, like the fly whose unfortunate landing site immortalized its iridescent eyes and hairy legs in excruciating digital detail while obscuring a couple of manuscript images. But mostly they discuss how to keep a steady stream of images flowing, the files properly organized.

The palimpsest imaging system exploits three basic strategies. LEDs on tripods in each corner of the camera room can bathe a manuscript page in light of a specific color or wavelength range, from ultraviolet to infrared. Each color interacts with ink and paper in different ways, allowing the camera to capture a series of slightly different images.

Next there’s back and side lighting. Sometimes the undertext ink is gone, but infinitesimal grooves remain where the ink ate into the animal hide. These etchings can be illuminated because the grooved parchment is thinner, allowing more backlight to shine through. This technique had never been applied to palimsests. The side lighting works similarly, creating tiny shadows in grooves and irregularities on the pages.

Finally, there’s fluoresence — a favorite of both real and TV crime scene investigators. Whether dealing with blood at a crime scene or parchment, fluorescence works the same way. When light of some wavelengths hits certain organic materials, their molecules absorb the light, then reemit it at a different wavelength. Filters bring out the resulting glow. With manuscripts, the organic material is the animal-skin parchment. Ink blocks some of its fluorescence, making it appear visibly darker in photographs.

“Probably nothing we do is unique,” says Bill Christens-Barry, the team’s electronics guru, who works as an independent contractor based outside Baltimore. “But we’ve found ways of optimizing each of these techniques.”

Under some of these imaging conditions, undertext shows up more prominently. Computer programs essentially subtract the difference between images where both types of text are prominent and those where mainly overtext is visible. The differences are converted into color: In some processes, undertext becomes remarkably legible in an artificial red, and overtext is suppressed in a muted gray. If that technique doesn’t work, the team can perform more complicated analyses and digital manipulations to bring out the text.

So far, the technological challenges at the monastery have proved surmountable. But one hurdle besides a multi-year workload remains. Some of the manuscripts are now so fragile that they can’t be handled without specialized facilities that the monastery doesn’t yet have. But if all goes well, a $4 million renovation will soon transform one wing of the monastery to fill this and other needs. The St. Catherine Foundation, an organization Britain’s Prince Charles launched after a visit in 1995, is raising money.

There will be a library offering access to key manuscripts and storage space for others. The facilities will have advanced fire suppression systems and two sets of doors to prevent wind from blowing in granite dust, which scrapes away at pages and is the desert’s greatest conservation challenge.

There will also be spaces dedicated to document conservation and study. This will include equipment for temporarily humidifying brittle pages to prevent damage during research or imaging. Without that, some pages would crumble on contact. The space will be long enough to allow scholars to work with entire scrolls. Two more imaging stations will be added for Father Justin’s digitization work, done with an assistant from the local Bedouin tribe, with which the monastery has strong relations.

The foundation has supported interim upgrades to storage facilities now filled with bar-coded storage containers Father Justin scans with his iPad to check contents. Such work already stands as an example of what can be done — and what should be done — to protect ancient manuscripts.

Though the group hopes construction can begin this year or next, a date hasn’t been set. Major work in such a place takes extensive planning. And maintaining the historic integrity of the monastery, a United Nations-designated World Heritage Site, adds challenges. It’s best not to use a jackhammer when you’re working next to a 1,500-year-old wall, for instance. Political uncertainty is forcing caution, as well.

None of the political turmoil in Egypt has posed a direct threat to the monastery, which has survived other upheavals. “They’ve been there since the 6th century,” Toth says. “How many of these things have they gone through?”

Several tourists have been kidnapped en route to or from St. Catherine’s by Bedouins seeking attention during the government’s transition. These events, while taking a heavy toll on tourism, have remained relatively peaceful, with captors treating prisoners like guests and releasing them physically unharmed.

But preservation protects against trouble in many forms — including the accidental variety such as fires and water damage. Once digital images of documents are sufficiently distributed around the world, the information they contain becomes exponentially safer.

As Doug Emery, an independent database handler in Baltimore whom the team calls its Lord of Minutiae, puts it: “We believe the way to protect books is you hold them close, and the way you protect digital data is you give it away.”

Just what information the palimpsests hold remains to be seen. To date, the team has imaged hundreds of pages from 14 palimpsests. Ultimately, these images will go to a team of 18 scholars with expertise in an array of languages, led by Claudia Rapp, a medieval text specialist from the University of Vienna. Eventually, the images will be available to all scholars around the world through an online database overseen by the monastery.

No one can say what the group will find — there could be key biblical or scientific texts or more forgotten languages.

“There are vibrant communities that made major intellectual, artistic and spiritual contributions, but their voices have largely been lost from history books,” Phelps says. “The hope is that we will recover these voices to fill in blank chapters in our shared history and allow these communities to speak to us again today.”