Will Lane is the grandson of Crosby Lane, a retired Railway Express guard, who confides in Will the story behind the pocket watch he keeps in a special place. As he grows into early manhood, he continues to listen to his grandfather, and learns a number of remarkable facts that are closely associated with this watch. Claudius A. Tucker, a black man, became a good friend of Crosby Lane. He was a genius and a self-taught master of mechanics. He built things before they became common, and was years ahead of the great inventors of that era. Fearful that unscrupulous people would abscond with the quiet fortune he had amassed, he made the watch Crosby Lane guarded so carefully and linked it with the means to protect millions of dollars for his grandchildren's inheritance. Both romance and heartbreak are woven through this story of life in the early part of the twentieth century, a story that ends with one of Tucker's grandchildren meeting a challenge to encounter and solve a world-wide problem.