Alexander Grekov bends his head over the scattered pieces of painted plaster for the millionth time, peers intently at them through his thick spectacles, and tries to see the giant jigsaw puzzle through fresh eyes.
That is not easy when you have been working on the same picture for nearly 15 years. But Mr. Grekov never expected that it would be easy to reconstruct a churchful of medieval frescoes that had been blasted to smithereens during World War II.
"When I first came here in 1965, I was quite certain that nothing could be done," he remembers, pointing to an old photo of a weed-clotted hummock, dotted with bushes, that was once the site of the Church of Our Savior of Kovalyovo. It was built in the 14th century outside this ancient Russian city.
"But we scratched about a bit, and I found some chunks of plaster that have chained me to this place forever."
Grekov's remarkable work is only the most excruciatingly painstaking aspect of one of the world's great endeavors at architectural restoration, under way now for more than half a century.
The object of this enterprise is nothing less than the city of Novgorod - the oldest town in Russia, and one that boasts a unique collection of buildings dating from every century since the 11th.
Such buildings would need restoring wherever they were. But the need was especially great in Novgorod because for 2-1/2 years during World War II, the front line between the Nazi and Soviet armies ran slap-bang through the middle of town. The scale of destruction was catastrophic.
And there had been much to destroy. In the 12th century, Novgorod was a bigger city than Paris or London, a prosperous trading center on routes running from the Baltic to Constantinople and into Asia. It was a member of the Hanseatic League, wealthy merchants endowed richly painted churches, and the town was protected by its surrounding marshes from invasion by the Tatar horsemen who ravaged the rest of Russia.
Even before World War II was over, the task of putting Novgorod back together had begun, and the town - with its walled and turreted Kremlin within a moat and its clusters of golden-domed churches - became a showpiece of Soviet restoration.
Challenges to restoration
But, says Nikolai Grynov, director of Novgorod's historical museum, "with hindsight, we might think the restoration could have been done differently." The restorers were skilled, but "socialism was a system that built faades, and in the Soviet Union you had to fulfill your plan. You couldn't spend 15 years on one church if the plan didn't say so, even if it needed it."
An example of the sort of problems restorers are facing now - apart from a chronic lack of funds - is the early-12th-century Nikolsky Cathedral. Today a massive reconstruction project has filled the air inside the church with masonry dust instead of the incense that worshipers used to breathe, and the sparks from oxyacetylene blowtorches are brighter than any candles.
It is not just a question of keeping the ancient structure up, although that is a difficult task, and one that local builders have been attempting for many generations; Yelena Skiptsova, the architect in charge of the current work, keeps coming across traces of her predecessors' efforts.
The dilemma is which Nikolsky Cathedral to restore? Hardly had it been completed in 1113 when workmen began alterations that continued through a major refurbishment in the 16th century, when four of the five original onion domes were removed, and a strange remodeling in the 18th century that left the early medieval Russian masterpiece with a classical Greek faade.
Restorers decided to go back to the original style but to keep bits of each restoration to maintain a record of nearly a thousand years' worth of work.
They had to reinforce all the foundations and walls, making them strong enough to take the weight again of the four old-new domes; they had to dig away several feet of soil and organic material that had accumulated over eight centuries and blocked the original doors; and they have re-opened the original windows in their original shapes.
This has involved some guesswork. The architects don't know, for example, the exact dimensions of the original cupolas they are re-creating and are using early illustrations as guides. But sometimes they find some unexpected tips.
In one corner of the church, as restorers pulled away at 19th-century alterations, they came across a brick wall that had been built in the 13th century over an original window, and behind that wall, three panels of ancient wood.
Some 13th-century laborer had been too shoddy to take the shutters off the window he was blocking up and had simply bricked over them. "He left us the evidence that there were wooden shutters on the first windows," Ms. Skiptsova says.
But she hasn't been so fortunate with the early frescoes in the Nikolsky Cathedral. "They did too good a job in the 17th and 18th centuries; they were very careful to remove all the existing frescoes before they painted new ones," Skiptsova laments.
In another Novgorod church, man's destructiveness has, paradoxically, saved the earliest and rarest frescoes. The Church of the Annunciation lost its roof to a Swedish artillery barrage in 1611 and was left open to the elements through most of the 17th century.
The walls, built of a chalky stone, got damp and exuded a thin ocher film that filtered through the porous 12th-century frescoes and hid them from view. In effect, it preserved them. When later artists came to redecorate the church, they simply painted over the top, and their work was easily removed by restorers who discovered beautifully expressive Byzantine frescoes beneath.
It is that sort of beauty that Alexander Grekov, now in his 80s, and his wife, Valentina, have been trying to piece together from hundreds of thousands of tiny bits.
They started by digging in the mound of rubble, which was all that remained of the Church of Our Savior, until they were stopped by the Army because they were coming across too much unexploded ordnance.
The enforced pause, while the mines and shells were cleared, gave Grekov time to think that maybe the frescoes, being made of plaster, had been shaken off the walls by shocks and vibrations before the walls themselves had collapsed. With the aid of prewar illustrations of the church, he estimated where each fresco would have fallen, divided up the floor plan into quadrants, and went back to work.
"This approach was the key" to putting the bits back in their proper place, Grekov says now.
Four years of digging yielded enough pieces - all carried into town by horse and cart - to fill thousands of trays, each labeled and numbered. Most of them are still stacked floor to ceiling, on tables and under tables, the length of the low vaulted workshop under the Novgorod Kremlin walls where the two Grekovs work with their single assistant.
"On a good day, on a really good day, I put about 12 pieces together," says Alexander with a broad smile, as he scans the delicate pastel colors and mournful faces of a composition showing Christ being brought down from the cross. "You have to like this kind of work.
"We have established iron discipline," he adds. "That was the only way to do the job."
So far, the Grekov team has reassembled as much as will ever be possible of some 20 frescoes, some small, some larger than life-size. Altogether, they collected enough pieces to reconstruct about half of the painted surface of the church walls, but Alexander Grekov knows he will never see the finished work.
"I haven't time to retire," he laughs. "But even if we live to 120 there will still be a lot left to do."