THE SEARCHERS Emotional Reunion of Father and His Long-Lost Twins, More Than 40 Years in the Making, Airing on "20/20," Friday, November 13, 10 pm ET on ABC

— -- It was a story that seemed to capture the world – U.S. Army veteran Allen Thomas using social media to search for his twins, who disappeared from his life in Korea nearly half a century ago. His simple plea on Facebook: “My name is Allen Thomas and I am looking for my son and daughter… I have been searching for decades…” generated an immediate and overwhelming worldwide response. Yet after over one million shares, retired Sergeant Thomas was no closer to solving the mystery of what happened to his son and daughter, born to his former Korean wife. That is when “20/20” teamed up with investigative genealogist Pamela Slaton, whose passion is re-uniting people, to work with Thomas and his daughter Charlene on their emotional quest. From Korea to Washington State to our nation’s heartland, “20/20” follows the twists and turns that end with a miraculous reunion more than 40 years in the making.

Elizabeth Vargas’ report, part of her “Searchers” series, airs on “20/20,” on FRIDAY, NOVEMBER 13 (10:00-11:00 p.m., ET) on ABC.

“20/20” is anchored by Elizabeth Vargas and David Muir. David Sloan is senior executive producer.