 Part owner of the mine, Potter Hood, and the railroad president, Horace Moore, search for the mysteriously disappeared train and gold.They are unaware, however, that the criminals are working secretly for Sam Slater, the other partner in the gold mine, who wants to sabotage mine operations enough that he can take over completely.Potter's son, Tom Hood, arrives home from college and determines to solve the mystery with the aid of his pal Bob Collins.