She pulls out a family photo album filled with faded snapshots of the handsome young man. In one image, he is with his high-school sweetheart; in another, he strums a guitar. A photograph from July 1970, taken just before the 18-year-old Dung headed south to the front along the Ho Chi Minh trail, shows him dressed in his North Vietnamese uniform, smiling and confident. Finally his mother unfolds a worn letter, dated March 1972. “My dear beloved family. We are ready to go to battle,” Dung wrote from Dak To in South Vietnam’s Central Highlands. “But please don’t worry for me. Spring is here.”

After the letter, Hy, who is now 72, never heard from her son again. She only knew that the battle for Dak To had been a particularly bloody one. For the next three years, she held on to the hope that he had survived. Then in 1975, soon after Hanoi’s forces captured Saigon, several solemn local officials visited her Hanoi home and told her that because there was no record of Dung’s body having been found or buried, he had been listed along with the more than 300,000 soldiers who fought for the victorious communist side as mat tich, or missing. At that sad moment, Hy vowed that she would do everything in her power to find him.

Poor, war-devastated Vietnam has no formal system of finding its missing. So upon hearing the news, Hy joined the ranks of thousands of families who, using their own money and resources, scour military archives, southern battlefields and graveyards in search of their missing loved ones. First she wrote letters to all the districts and villages in Kontum province where Dak To is located and went on television to ask viewers for information about Dung. Then she tracked down members of Dung’s regiment who had led the successful attack on Dak To’s airfield and town and asked them for information. They told her that Dung had been killed in the initial assault on the airfield and that a transportation unit had been left behind to bury the dead. She finally found someone in the transportation unit who said they had buried Dung along a footpath, near a stream on the edge of a forest and in sight of a mountain. So in 1976, Hy and her partially crippled husband-he had been wounded twice in the war of independence against the French-began a long journey to Dak To.

It was the first of five trips she would make to that remote, mountainous region during the next several years. She and her husband were joined by her younger son, Thang, and several members of Dung’s old regiment. To get to Dak To, they took trains and buses, rode in old jeeps and straddled the rear seats of motorbikes as they made their way over bumpy back roads. Sometimes the group would camp, eating instant noodles and drinking water from streams. When they arrived at the forest they planned to search, they would map out strategies and routes.

The excursions were exhausting. Guided by local officials or soldiers, they would sometimes have to cut their way through the thick forests with machetes. Hy’s face and body was often cut by sharp leaves and thorns. Bees, ants and leeches attacked her. She forded streams that came up to her chest and climbed hills and mountains. “Many times I barely had the strength to go on,” she says. “Every time I came back from a trip I was ill. Once I came back almost paralyzed.” Still, she persevered.

Unfortunately, the rugged landscape around Dak To had changed radically, and the landmarks that Dung’s comrades had told her about no longer existed or weren’t readily apparent. In desperation, Hy hired a clairvoyant, who told her that Dung was buried in one of several military cemeteries in the region. That proved to be a dead end as well. She searched in 17 locations where she hoped to find his remains, each time digging up all the unmarked graves she could find. Mostly they contained only canteens, spoons, broken bowls and shreds of hammocks. “I jumped into the holes and clawed through the dirt looking for remains but we found none,” she recalls. When people asked her how she would recognize Dung’s remains if she found any, she replied: “By his teeth. He had very beautiful, straight teeth.”

Finally, she began scooping up pebbles from streams she had crossed and handfuls of dirt from the graves she had opened, depositing it all in a bag she carried with her. When she arrived home, she placed the contents into an urn and buried it in the family’s cemetery. She engraved Dung’s picture, his age, his unit and Dak To, the name of the battle in which he fell, on his tomb. She and her family still visit the grave often. “It’s a form of consolation and a place where the family can gather and remember him,” she says.

Despite having already created a resting place, Hy still wants to find him. “I can’t bear to think of him laying unknown, alone on some distant battlefield,” she says. Dung’s friends from the regiment have invited her to go back and make one last search. “Perhaps,” she says, “I’ll go again if my leg gets better.”

And she says she completely empathizes with the mothers and wives of American MIAs. “American mothers and wives must hurt more than we do,” says Hy. “Their loved ones fought in a strange country and died on foreign soil very far from home.” Dung may never be found, but at least he’s in his own homeland.