Thirty years ago, a small group of mothers whose children had been seized by the military government then in power in Argentina began walking in circles in the main square in Buenos Aires.
By Daniel Schweimler
BBC News, Buenos Aires
The mothers' protest has become a fixture in Argentine life
They marched in desperation because they didn't know what else to do.
Their children - teenagers and young adults - had been taken by government agents to illegal detention centres. There was no record of their arrest; many of them have never been seen since.
They were some of the estimated 30,000 Argentines who became known as the disappeared, killed by the ruthless military government that held power between 1976 and 1983.
The mothers have been marking the 30 years since they took those first desperate steps with a series of events in Buenos Aires and the rest of Argentina.
And they are marching still, every Thursday afternoon outside the government palace in the Plaza de Mayo. They wear headscarves which bear the names of their loved ones and carry photographs.
They say they still don't have the answers to all their questions and they want the killers and torturers to be tried and put behind bars.
The women became known as the Mothers of the Plaza de Mayo and are now a major force in Argentine politics, with a message and an influence that have spread around the world.
Other groups grew from the Mothers: the Grandmothers of the Plaza de Mayo who search for their grandchildren, taken from their murdered parents and given for adoption to childless police or military couples.
Hebe de Bonafini says suffering has made them stronger
They estimate that several hundred were taken and have so far traced more than 80 and reunited them with their real families.
Then there are the Hijos - the children of the disappeared who work together to demand justice for the kidnapping and killing of parents who most of them barely knew.
One of the founders of the Mothers of the Plaza de Mayo and its current president is Hebe de Bonafini. Two of her children were taken by the military.
She has become a high-profile figure, working closely with the current Argentine president, Nestor Kirchner, and travelling the world in her fight for justice.
She's a friend of Cuba's Fidel Castro and the president of Venezuela, Hugo Chavez, among others.
Sitting in the office of the Mothers of the Plaza de Mayo near the Congress building in Buenos Aires, she spoke of the early days of the organisation.
"We kept learning and growing, each day getting a little stronger," she said.
"And the more pressure they put on us, the stronger we grew. They kidnapped three of our members in 1977 and we came back. They destroyed our headquarters and we came back. We're a different organisation now but I never would have dreamed that all those things would have happened."
Martin Fraga lost both his parents when he was just a few months old. He is now a member of Hijos and I met him on an "escrache".
An escrache is a demonstration held outside the house of a member of the military government who the protesters feel has not been punished for their crimes.
Shortly after the return of democracy in Argentina in 1983, the military leaders and those who worked for them who had been found guilty and sentenced were given a pardon by the government.
Men with blood on their hands were allowed to go free and lead their lives as though nothing had happened. The escrache is designed not to let that happen.
Neighbours are informed about who they're living next to, slogans are daubed on walls and the road, posters of the victims taped to lampposts.
"It's not revenge I'm after," said Martin. "But the men who carried out these crimes should be behind bars. They should have been behind bars 20 years ago."
Ximena is another living victim of Argentina's military government. Both her parents were kidnapped when she was eight months old. She was placed in an orphanage and adopted by a childless doctor and his wife.
Eight years later her grandmother found her, simply turning up at the door of the family she thought was hers.
While the long legal process to return her to her rightful family was under way, she lived between both households in two different cities.
For a while she was placed under constant police guard to stop her being taken from the country.
"I try to look to the future," she said. "Because the military wanted to steal my future. This is my way to find justice. I want to study, have a family and find out the truth because the military did not want us to find the truth."
She's 29 years old now, older than her parents were when they died. She is studying to be a veterinary surgeon and hopes to starts a family and travel.
"One day I will have to tell my children what happened to their grandparents," she added.
After many years in which successive democratic governments in Argentina either could not or would not seek justice for the dark years of military rule, there are now strong moves by President Kirchner to find answers and put some of the killers and torturers in prison.
Many ordinary Argentines also found it difficult to deal with a past which was often easier or more convenient to forget.
The fight to know what happened during the Dirty War goes on
The former police chief, Miguel Etchecolatz, was last year sent to jail for his part in the kidnapping and killing of many people in the city of La Plata.
But one of the witnesses at that trial, Julio Lopez, has disappeared, feared abducted as a reminder that those agents of terror are still at large.
Many of the culprits have died and those who haven't are old.
But the fight for justice in Argentina goes on and the Mothers of the Plaza de Mayo keep marching.
They, too, are old. But they're joined now every Thursday by supporters of all ages, foreign tourists, other human rights groups and passers-by to carry a powerful message which began 30 years ago with a few tentative, frightened steps.