Martina Metzler peers at the piles of paper strips spread across four desks in her office. Seeing two jagged edges that match, her eyes light up and she tapes them together.
"Another join, another small success," she says with a wry smile -- even though at least two-thirds of the sheet is still missing.
Metzler, 45, is a "puzzler," one of a team of eight government workers that has attempted for the last 14 years to manually restore documents hurriedly shredded by East Germany's secret police, or Stasi, in the dying days of one of the Soviet bloc's most repressive regimes.
Two decades after the heady days when crowds danced atop the Berlin Wall, Germany has reunited and many of its people have moved on. But historians say it is important to establish the truth about the Communist era, and the work of the puzzlers has unmasked prominent figures in the former East Germany as Stasi agents. In addition, about 100,000 people annually apply to see their own files.
The Stasi, which is said to have had more than 170,000 informers, succeeded in destroying thousands of files, shredding them in machines called "ripping wolves" until the equipment broke down under the weight of the task, then through burning and pulping (the contents, held in buckets in the archive, are known as "Stasi porridge"). At the end, agents tore them by bare hand as the teeming crowds smashed down their doors.
The shredded files, which any good German bureaucrat knows as vorvernichtete Akten or pre-destroyed files -- fill a staggering 16,000 mail sacks that contain about 45 million individual pages, or 600 million scraps. Thus far, the puzzlers are 440 sacks into the process.
"If we carry on at this pace we'll still be here in 500 years' time," says Ernst Schroedinger, a 54-year-old former amateur boxer turned puzzler.
The puzzlers work in a former asylum seekers' application office in Zirndorf, a small town in deepest Bavaria. Entrance to their salmon-colored building is via a high-security electric gate. On entering, one is struck by the acidic smell of the paper, and by the dust.
The linoleum floor, the milk glass doors, and the absence of computers, as well as the map on the wall that shows the Soviet Union and the GDR, or German Democratic Republic, as East Germany was known, all provide a sense of stepping back in time.
Schroedinger works 41-hour weeks and averages a sack a year restoring documents on the Stasi's surveillance of the army, media, railway and church.
The few files that have so far been pieced together hold piquant details about life in the GDR. Among them are 1,000 pages of the dossier of Sascha Anderson, an avant-garde artist who was in the service of the Stasi but always denied any deep involvement. The file showed the extent to which Anderson betrayed fellow artists and dissidents.
There was also the file of Heinrich Fink, a theology professor who was exposed as the spy "Heiner" who regularly informed on students and colleagues. Other prominent cases involve former Red Army Faction terrorists who were harbored by the Stasi, and a Berlin sports doctor who doped East German athletes.
This month, Metzler has been piecing together documents relating to the life of Stefan Heym, a late German-Jewish writer who chose to live in the GDR but was frequently at odds with the regime and was spied on relentlessly.
"I've just found the sketch of his children's bedroom drawn on orders from the Stasi by his cleaning lady, who they code-named 'Frieda,' " says Metzler, who reads thrillers in her spare time to relax.
The pencil sketch shows everything from the position of the doors and windows, to the cupboards and rugs.
"However many documents I piece together, it'll never cease to amaze and shock me the extent to which friends, colleagues, even husbands and wives, went to betray each other. It shows you what a poison regime it was," she says.
The puzzlers' work helps prevent the public from forgetting how bad the East German regime was, Metzler says.
"Put it this way, I used to think, why do they keep regurgitating all the stuff about the Hitler regime that happened over 60 years ago," she says. "And now, since working here, I know why the reconstruction work is so important, so that we don't forget, and that's what motivates me when some people say our task is hopeless and leads nowhere."
She bristles slightly when asked how she keeps up such an apparently thankless task every day.
"You wouldn't ask a baker what drives him to get up and bake his bread," she says.
The thousands who apply to see their files would probably agree. In addition to providing a historical record, the files can help people clear their names. Some, for instance, apply to gain proof that they were unjustly imprisoned by East German authorities, which may help them clear criminal records that prevent them from getting jobs or help them claim compensation for being persecuted.
At one point, there were about 45 puzzlers, but those who quit or retired have not been replaced. They are paid a standard German bureaucrat's salary of between $29,600 and $37,000 a year.
Year in, year out, a small delivery truck brings more of the 16,000 sacks to the puzzlers' work space and returns reconstructed dossiers to Berlin.
The puzzlers are eventually due to be assisted by a computerized machine, known as the E-Puzzler, developed by scientists at the Fraunhofer Institute, the same lab that created the MP3 format. The E-Puzzler, believed to be the world's most sophisticated pattern-recognition machine, would work by scanning the small paper strips into a computer image file and analyzing their texture, shape, thickness and tear patterns to compose a digitalized image of a whole document.
Its go-ahead, however, depends on political will. The whole project has attracted criticism from left-wing lawmakers and erstwhile members of the East German Communist Party, who argue it is a waste of money.
"I resent the fact that East German biographies are being dragged through the mud," said Egon Krenz, East Germany's last Communist leader, who spent 6 1/2 years in prison for his role in the regime. "I'd say they could use the money more effectively elsewhere, just like when they invested in East German autobahns in the early 1990s, which is something everyone can benefit from."
So far, $9 million has been allocated to the project by the German Parliament, but much more would be needed to install and maintain the E-Puzzler.
Former leading East German dissident Baerbel Bohley said Germany cannot afford to halt the project.
"You cannot put a price on the importance of this," she said. "There is so much potential in the files, to find out who did what to whom, and in order for historians in later years to be able to understand how a totalitarian regime comes about in the first place."
On a recent visit to the former Stasi headquarters in Berlin, Chancellor Angela Merkel, who grew up in East Germany, said the large number of applications from people wishing to view the information the Stasi held on them showed that people want to know more, even if the truth is bitter.
"To have the knowledge about what happened is for the majority better than not having that knowledge, or not being allowed access to it," she said.