Just as she does every Thursday, Taty Almeida ties her white scarf around her head, grabs her cane and joins her fellow octogenarian protesters to march around the square outside Argentina's pink presidential palace.
Defying their advancing years, the bereaved mothers making up Argentina's most famous human rights group still gather here every week, demanding answers on what happened to the children they lost during the country's brutal military dictatorship.
The Mothers of May Square -- Madres de la Plaza de Mayo in Spanish -- turns 40 this week, a milestone that finds its members increasingly frail but ever determined to see their children's killers brought to justice.
The group was born on April 30, 1977, when 14 women gathered to protest the military dictatorship installed in a coup the year before.
They dared to challenge the regime at a time when repression was at its height.
They risked the same fate as their political activist children -- torture, death or simply disappearing without a trace.
Instead, the generals tried to laugh them off as "the crazy ladies of May Square."
"We were crazy -- crazy with pain, with rage, with powerlessness," says Almeida, whose dyed chestnut hair and fiery eyes belie her 86 years.
But "we transformed that rage into love, into a peaceful struggle," she tells AFP.
Almeida's son Alejandro disappeared on June 17, 1975, in the run-up to the coup. A 20-year-old medical student, he was also a member of the People's Revolutionary Army, a leftist guerrilla group.
He was one of 30,000 people "disappeared" by the regime or right-wing death squads in the 1970s and 1980s.
- Secret struggle -
Almeida, who came from a military family, was reluctant to join the Mothers at first.
"I didn't dare to go. Given who I was, I was afraid they would accuse me of being a spy. But once I joined the group, it was a revelation," she says.
Almeida is a retired school teacher. Many of her fellow members were housewives. Few had ever been involved in politics, and many were surprised to learn their children were in leftist militant groups.
But they found themselves caught up in the same struggle against the regime.
Soon, a sister group was born: the Grandmothers of May Square, who discovered their abducted daughters had given birth in captivity.
An estimated 500 such babies were stolen and illegally adopted, often by families close to the regime.
- Fighting not to forget -
At that first protest, the 14 mothers stood still in front of the Casa Rosada, the presidential palace, holding up pictures of their missing children.
Surprised by the unexpected protest, police ordered them to walk instead, since public gatherings of more than three people were banned.
So two by two, they marched around a statue in the square.
The group has been doing that ever since, even after the dictatorship fell in 1983.
Today they are joined by dozens, sometimes hundreds, of young admirers and fellow activists.
They got a champion for their cause when late president Nestor Kirchner came to power in 2003.
After his leftist government took office, hundreds of retired military officers have been tried and jailed for dictatorship-era abuses.
But many dark secrets remain.
"We don't know where (our children's) remains are. We can't mourn them. We can't lay flowers at their graves. There's nothing more cruel," says Almeida.
Instead, they march.
Their rallying cries have evolved over the years.
The slogan at the first protests was, "We want them back alive."
Today, one protester intones the names of the disappeared. The others reply "present" after each one.
It is a way of fighting to not forget.
"The crazy ladies are still here," says Almeida. "And we are still on our feet."