Standing in what was her father's office before he was executed, Genden Tserendulam points to 65-year-old pictures on the walls that tell a chilling story.
There are young families, nomadic herders, Buddhist monks and students. And there are the Mongolian officials who had them murdered.
Tserendulam's father, Peljid Genden, was Mongolia's prime minister in the mid-1930s when its communist leaders began bloody purges at the urging of their Soviet patron, Josef Stalin.
Genden was one of the first victims. He was killed in 1937 after resisting directives from Stalin, who also was ordering the slayings of millions at home.
By the time Mongolia's terror ended in the mid-1950s, after periodic spasms of bloodshed, as many as 100,000 people had been executed--a heavy toll in a country that even today has only 2.4 million citizens.
Yet so secretive was Mongolia that 11 years after it discarded communism, its people are still trying to learn the true extent of the horror.
"There is no accurate figure for the number of the dead," said Tserendulam, 74, who has turned the Swiss chalet-style building that housed her father's office into a museum about the killings.
With financial help from the post-communist government, the retired physician collects documents and interviews elderly survivors.
"There are a few thousand left. Sometimes I interview one and he dies the next week," she said.
Mongolians have eagerly embraced elections, the Internet and other trappings of post-communist life, but they seem unsure how to deal with a time when a peaceful Buddhist society of pastoral nomads turned so savagely on itself.
Everyone has a story of a murdered relative. Yet Marshal Choibalsan, Mongolia's Stalin and leader of the purges, is still officially a national hero. His statue stands on a downtown street in Ulan Bator, the Russian-style capital whose tree-lined avenues and pastel public buildings look jarringly out of place on the rolling Mongolian grasslands.
After popular protests led to multi-party democracy in 1990, Choibalsan's former party repudiated its communist past and embraced free enterprise and democracy. It was voted out of office in 1996 but returned to power last year with a resounding victory in parliamentary elections.
The government issued an official apology last year for the killings. It came in a speech by Prime Minister Nambar Enkhbayar on Mongolia's Day of Politically Persecuted Victims--Sept. 10, the date in 1937 when the purges began.
But Enkhbayar insisted the party itself also was a victim. He pointed to a huge death toll among its members and their families.
Others shift the blame to Stalin, though Mongolians did the killing.
After a long, murderous reign, Choibalsan died in 1951 in the Soviet Union. Mongolians believe he was killed on Stalin's orders, which some think makes him yet another victim.
Former communist officials say Choibalsan had no choice but to make Mongolia a Soviet puppet. The country had won independence from China in the 1911 collapse of the last imperial dynasty, and had nowhere else to turn for help to resist being reconquered.
Propaganda posters in Tserendulam's archive capture the fear of the 1930s, depicting Chinese as giant ogres snatching up and devouring Mongolians.
"We had just one choice--be as close to Russia as possible to ensure our independence," said Sangaa Bayar, chief of staff for President Natsagiin Bagabandi, who was the governing party's deputy chairman during its communist days.
Embracing Stalin's tactics, Mongolia's communists killed anyone who might stand in their way, and then thousands more to cow the survivors into obedience.
Tserendulam has collected names of 28,185 people killed in 1937-39 alone. Some 17,000 were Buddhist clergy, whose influence the communists feared. Also targeted were members of the Buryat and Kazak ethnic groups who had fled the Soviet Union's Marxist revolution.
Tens of thousands more were killed in the countryside, Tserendulam said. Firing squads desperate to fill quotas grabbed herders at random.
Tserendulam's father was a leading communist, but no radical. Unlike the Soviets, who banned religion and private property, Genden let Buddhists keep their temples and nomads their camels and sheep.
Tserendulam was 9 when Genden was dismissed in 1936 after rejecting Stalin's demands to destroy the Buddhist clergy and give Moscow more control. By one account, their argument in Stalin's Moscow office was so heated that Genden broke the Soviet leader's pipe.
Mongolia's government exiled the family to the Soviet Union, where they were held for 15 months in a town on the Black Sea. Genden's family last saw him one day in 1937 when police took him away after lunch.
It was another 54 years before Tserendulam learned his fate. Confirmation came in a 1991 letter from then-Soviet leader Mikhail Gorbachev: Genden was executed on phony spying charges.
After Stalin's death, Genden had been posthumously declared innocent by Moscow in 1956, yet so firm was Mongolia's commitment to Stalinist terror that word never reached his family.
Tserendulam, sent home in 1938, was hounded out of school but later allowed to complete her education. She practiced medicine for 49 years. Her husband is a physicist.
Tserendulam opened the Memorial Museum for Victims of Political Persecution in 1992.
Genden's office has been refurbished, complete with an oversize black, 1930s-vintage telephone and a painting of him in a traditional Mongolian robe. Next door is a room lined by floor-to-ceiling panels with 12,500 names--the start of a list that Tserendulam says will include every known victim.
The museum is a regular stop for field trips by schoolchildren.
"I am doing this to make sure that everyone knows what happened and to make sure it doesn't happen again," Tserendulam said.