In 1971, a 25-year-old high school science teacher named Jim Roberts found himself in a muddy hamlet 50 miles outside Saigon, a “wide spot in the road,” as he called it, where the long slog of the Vietnam War felt particularly endless and futile.

Roberts, the son and grandson of military men, had enlisted over the heated objections of his father, who feared he would never return alive to his small West Virginia hometown. For Roberts, an Army infantry 1st lieutenant, the Vietnam conflict had become a “lonely war.” Photos he took one day of two kind women he met during that tour have led him on a 50-year quest to find them and thank them for breathing a little joy into his life so long ago.

Roberts was part of a mobile advisory team, one of only five soldiers sent to Dong Xoai to live among displaced farmers and to train regional forces, assisting as observers and strategists when they went into the field to fight. He witnessed things so traumatizing that he still can’t talk about them five decades later.

“I don’t want to go back there and think about it,” Roberts, now 75, said in an interview. “We did what we had to do.”