After a stranger, claiming to be Mr. Hardy’s lawyer, ushers the boys onto the wrong train, resulting in their being kidnapped and later escaping, the Hardy boys decide to continue their journey in disguise, finally arriving at Lucky Bottom, Montana to meet with their father. He tells them that they are looking for gold which Bart Dawson claims was stolen from him by an outlaw named Black Pepper and his gang. The next day, while searching for the gold, the Hardy boys are attacked by the gang of outlaws; however they manage to escape and return to town for the night. The following day they manage to catch one member of the gang who gives them information about Black Pepper. Upon searching, they discover a cabin used by Black Pepper, and there they find a map to the hidden gold, indicating it is buried in The Lone Tree mine.