Arnold Miller had not seen his son Mason in five years. Toby Miller, Arnold's estranged wife and Mason's mother, had abducted the then 4-year-old boy. Miller spent two of those years and $15,000 in a heartbreaking search and, by the time he gave up hope, had founded Children's Rights, Inc., a clearinghouse of information about tragic cases like his own. There are more than 25,000 in the U.S. every year. That was the thrust of a story published in the March 19, 1979 issue of PEOPLE, along with a 1974 photo of the child during a joyous last trip with his dad to Disney World.

Last month the phone rang in Miller's Washington, D.C. home. A woman said she had read of Miller's plight in PEOPLE and had recognized Toby and Mason as former neighbors. She thought she knew where they were. "When a call like that comes you just drop everything and go," says Miller, 35, who divorced Toby in absentia in 1976. "You don't have time to worry about whether you can afford it or not. You just take the lead and track them down." He and his second wife, Rae, were en route in a matter of hours.

Their search took them to a community of Orthodox Jews in New York State, where Mason was said to be a student in a small yeshiva. Understandably, the reunion of father and son proved emotional, awkward, even frightening for both. "We went in like the Marines," says Miller, "but I was fighting to keep my cool; I wanted to make it a positive meeting." Instead, he says simply, "I cried." Before him stood a little boy wearing a yarmulke, his face framed by two soft brown curls. After his son's disappearance, Miller learned, the boy and his mother had lived in five states, from Massachusetts to Georgia. Mason had been steeped in the traditions of his mother's newfound orthodoxy and now answered only to his Hebrew name, Moshe. As he stood between Miller and the rabbi of the yeshiva, the boy was asked if Arnold was his father. Confused, he replied haltingly, "No."

"He knew who I was, but he was scared," Miller recalls, "and I was ready to throw in the towel—I didn't want him to bear the burden. I took his arm and said, 'Mason, everything is going to be all right. I love you very much.' " After the boy's shaken mother arrived, the group adjourned to the local courthouse. A judge promptly ruled that Mason should be allowed some time with his father. During their first hour alone, Mason scanned a family album and recalled the trip with his dad to Disney World. At meeting's end, says Miller, "Mason threw his body against the door and asked me not to leave."

The following morning the Millers checked into a hotel for a five-day reunion. Rae's son, Quinn Gummel, 10, was flown up from their Washington home to join them. He and Mason had been pals years ago, says Miller, and "took to each other again immediately. Quinn thinks it's neat having a little brother, and Mason is crazy about him." The boys shared bunk beds when the court subsequently ordered that Mason be allowed to spend part of the Passover holidays in Washington.

The 9-year-old arrived with detailed directives from his rabbi, which his father agreed to observe. (Miller himself had been raised in an Orthodox home, but was startled to discover that these "commandments" numbered not 10 but 613.) "I promised to honor Mason's religion and to make sure he said his prayers and wore his tzitzit," notes Miller, referring to a special undergarment that serves as a sign of the faith. "He only eats kosher food now. He hasn't had a Big Mac in five years." Rae found keeping a kosher house "no big deal," and she wowed Mason by roaring around in her Honda 200 motorcycle. "Women in his mother's community," according to Miller, "are like third-class citizen's."

A systems analyst for the U.S. Postal Service, Miller says the return of Mason won't weaken his commitment to Children's Rights, Inc. "My devotion is greater than ever to see that we get protective legislation," he vows. "It was just sheer luck that I found Mason."

Miller also intends to press for permanent custody of his son. Aware that the litigation is likely to be bitter and prolonged, he prefers not to discuss the case further. Ultimately, he hopes to tell his story—"a real adventure," he calls it—in his own way. "I've wanted to write a book about my search for Mason," he explains, "but until now I've hesitated because it didn't have a happy ending."