BUENOS AIRES — In the end it was his father’s left hand, found a couple of years ago in a pile of charred bones outside La Plata, that enabled Gonzalo Reggiardo Tolosa to know for a fact the man he never knew was dead. This was physical knowledge, different from the almost-certain supposition with which he had lived ever since he discovered as a boy in the late 1980s that the couple who raised him and his twin brother Matías were not his parents.

Even his father’s remains did not constitute closure for this child of the “disappeared,” born in 1977 under the rule of Argentina’s military junta, seized at birth from parents who vanished into the vortex of the “Dirty War,” raised by a police officer named Samuel Miara and his wife Beatriz who initially insisted he was their son, thrust into foster care after Miara was jailed, then handed over to a biological uncle, told to forget his former life, and finally left to sift through the scattered fragments of his existence.

Still the trials go on.

“I am incredibly mad at the cruelty of not allowing a person to mourn his parents,” Reggiardo Tolosa tells me. “They did all they could to destroy the evidence. The other day I left the witness stand after giving testimony and broke down. I was sobbing. I am still trying to mourn my parents.”

We are seated in a Starbucks in the Argentine capital. It is a holiday, as usual. The streets are quiet — apart from the money-changers’ refrain: “Cambio, cambio, cambio.” Yet another little currency crisis has hit Argentina. Nobody wants pesos.

Reggiardo Tolosa speaks slowly of another time, when our sons of bitches, to paraphrase Franklin Delano Roosevelt’s apocryphal comment, did their foul business in the name of defeating communism in the Americas, and many thousands disappeared. His manner is gentle, his pain evident, still. This is what our sons of bitches wrought, a legacy without end.

His breakdown occurred last month. He and his brother were called to testify in a trial involving former army officers accused of involvement in killings under the junta at a clandestine facility called La Cacha, adjacent to Los Olmos prison in La Plata, where the twins’ parents were held before being “disappeared.”

One of the indicted, Ricardo Fernández, a former intelligence officer, is Gonzalo Reggiardo Tolosa’s godfather. His godfather! He was chosen by Miara, who always insisted, however, that Fernández had no role in abducting the twins. Now Reggiardo Tolosa is convinced Fernández was the conduit from the hell of La Cacha to the Miaras.

The twins arrived at the Miaras’ home on May 16, 1977. They have no birth certificate. It is estimated they were born around April 27. “What I must find out now is what exactly happened in those three weeks,” Reggiardo Tollosa says. Almost 37 years after he and his brother were taken, he is closing in on the truth.

I have known this man since he was a boy. His hair, now brown, was blond then. He and his brother were playing soccer in a yard in the Paraguayan capital of Asunción. I had followed a lead that the Miaras had fled to Paraguay with two boys born to a disappeared Argentine couple. Miara, when I confronted him in 1987, denied it. But the piece, published in The Wall Street Journal, helped secure his eventual extradition to Argentina.

Some stories will not leave you. They are your actual responsibility.

Reggiardo Tolosa is with his girlfriend, Jimena Vicario. She was a baby when, on Feb. 5, 1977, she was taken from her mother (who disappeared) during police questioning. She was dumped in a Buenos Aires hospital, raised by a woman who took pity. Her father, Juan Carlos Vicario, a Spanish citizen who fled Franco, was also murdered. The couple was about to leave for Spain when they vanished.

Jimena Vicario never gave blood for DNA testing, never wanted to know what exactly happened to her parents, never saw the point. Reggiardo Tolosa thinks she hates the tango and wants to get out of Argentina because that is what her parents were about to do when they were killed. For himself he cannot leave his football club (San Lorenzo), his city’s particular melancholy.

They first glimpsed each other as children in court. They re-met a year ago through Facebook. They laugh that there is so much they don’t have to explain to each other; that they don’t need to deal with in-laws; that money received in compensation for their loss disappeared in another currency crisis; and that they no longer have partners who, when angry, say: “Spare me your story yet again.”

They can laugh, just. The next trial, Reggiardo Tolosa says, will focus specifically on Fernández and the twins’ abduction. Perhaps then, he muses, “I will finish realizing I am an orphan.”