The mystery of Pfc. Paul Flagg is solved. Thirty-seven years later, the Marine I wrote in Vietnam and then lost has materialized. He is alive and well in Sumter, S.C.

Flagg's e-mail to me Monday morning answered the question I posed in a Veterans Day column in 1998: "Where are you, Pfc. Paul Flagg?"

I had gotten to know Flagg in 1968 through the U.S. mail and my brother, Jack. Both boys, for they were only 18, had gone through boot camp together at Parris Island, then Camp Pendleton, before shipping to Vietnam in February 1968.

Flagg was with the 1st Battalion, 9th Marine Regiment, also known as "The Walking Dead" for its killed-in-action rate (77.25 percent), the highest in Marine Corps history. Jack was with the 3rd Battalion, 9th Marines.

Both machine gunners, Flagg and Jack spent much of their time in Khe Sanh fighting the North Vietnamese regular army rather than Viet Cong guerillas. The Battle for Khe Sanh was one of the largest and most strategically important in the war. Thanks to shared family stories and photographs, Flagg came to know me, decided he needed a pen pal and began writing. I wrote back. I don't remember when we stopped writing - probably after my brother returned home - but we lost track. As I wrote in a 1998 Veterans Day column, I always wondered what happened to Flagg, but I always counted on his having made it back home.

That column prompted a flurry of e-mails from veterans suggesting how I might find Flagg. I followed up but without success. One veterans group notified me that he had returned to the United States. At least Flagg's name wasn't on the roster of the dead.

Several times in the intervening years, readers have written to ask whether I had ever found that Flagg fellow. Today the answer is yes.

I found him through a Kansas City reader, who knew a Paul Flagg in South Carolina, who had been a Marine in Vietnam. Perhaps he was the same one. Then Flagg e-mailed. When I called, I asked Flagg if he had known a certain Jack from central Florida.

Well, yes, he had.

Well, I'm his sister, the one you used to write, I said.

Well, whaddya know?

Today, Flagg is 54, married with one grown daughter and, at the moment, unemployed. He speaks with a smoker's rasp and the matter-of-fact tone guys get when they're not likely to be surprised by much. Not even a phone call from a long-ago pen pal.

We talked. Flagg told me he joined the Marines out of high school for "something to do." He remembered boot camp with Jack as "hell on wheels . utter humiliation every day." Continued...