Maria Fernanda Restrepo was 10 years old when her brothers, Santiago and Andres, disappeared in Ecuador's capital city Quito. More than two decades later she has released a powerful documentary film, which has prompted a new investigation.
The two boys, aged 17 and 14, had been left in charge of their little sister while their parents were on holiday.
On 8 January 1988, they took her to school and told her they would pick her up at a party that afternoon.
She never saw them again.
Santiago and Andres were kidnapped, tortured and murdered by police officers. Their bodies were allegedly dumped in Lake Yambo, two hours south of Quito, but have never been found.
Restrepo, now 34, had little more than a few family pictures and videos to remind her of her brothers. She describes the film as "a personal necessity" to help her get to know the family's history - "not to deny the pain, but to confront it", as she puts it.
While many books have told the story of the disappeared children before, Con mi corazon en Yambo (With my heart in Yambo), provides an intimate picture of the effect of the disappearance on the family.
Restrepo tells the story in the first person, remembering her mother crying inconsolably for days, and the tension and expectation that rose every time the phone rang.
As the camera slowly goes through the family home, where the boys' rooms remain untouched, viewers are drawn into their world.
The documentary also uses TV footage from the time, to document how images of Santiago and Andres were reproduced across the country, and how increasing numbers of people joined the family's weekly marches to call for justice in Quito's old town.
"This film is part of my life," says Restrepo. "It came out to tell the story of my 24 years of emptiness, without my brothers.
"When my brothers disappeared, I was only 10 years old; I thought they were going to come back. When there are no bodies, you have no funeral, and no time to cry.
"I learnt how to cry through this story."
Santiago and Andres were on their way to Quito's airport to say goodbye to a friend when they disappeared. It is believed that police officers stopped their car for an inspection, but it is unclear what happened next.
The police put forward different accounts, which were later dismissed.
According to one, the boys died in a tragic car accident. The police also suggested that the boys had run away from home, because - they alleged - Santiago was involved with guerrillas.
In 1991, as pressure grew, an international commission was set up to investigate the case. It found several agents of the National Police Criminal Investigative Service (SIC) responsible for the kidnapping, torture and death of the boys.
The SIC was eventually dismantled, and in 1995 seven police officers were convicted and sentenced.
The scale of state-sponsored human rights abuses in Ecuador does not compare with that in other countries in the region, such as Chile and Argentina, where thousands of people were tortured and disappeared under military dictatorships in the 1970s and 1980s.
However, according to Ecuador's Truth Commission, which released its findings in 2010, state-sponsored violence took place under the democratically elected government of Leon Febres-Cordero (1984-88). During that period, nine people disappeared, including the Restrepo brothers, and there were 310 victims of human rights abuses.
The SIC, which was established in 1986 to lead a crackdown on a guerrilla group active at the time, was responsible for many of those abuses.
Central to the findings on the Restrepo case was the testimony of a former SIC agent, who said that he collaborated in dumping the boys' bodies in Lake Yambo, after others had tortured them.
The lake was searched twice - the second time in 2009 with Ms Restrepo and her father present.
The footage of that visit to the lake features in the documentary, with close-up shots of the murky waters as the sonar and the underwater camera go in.
The film took seven years to make.
Since it opened at cinemas in Ecuador in October it has been seen by more than 160,000 people, making it the most successful documentary in the country's history. Such has been its impact that the interior ministry has promised to show it to police officers as part of their human rights training, and the attorney general has begun a new investigation.
Yellow posters have gone up across the country offering a $200,000 (£125,000) reward in exchange for more information.
"There are many questions that still need to be answered," says Restrepo.
"A family can do some things, and we've done a lot. But what's needed is the political interest to solve this and other cases.
"Finally there is a government interested in this case, and we hope it's a real interest."