"A fortune in hidden gold! That certainly sounds mighty interesting."

Frank Hardy folded up the letter he had just been reading aloud to his brother.

"Dad has all the luck," replied Joe. "I'd give anything to be working with him on a case like that." "Me, too. This case is a bit out of the ordinary." "Where was the letter postmarked?" "Somewhere in Montana. A gold-mining camp called Lucky Bottom." "Montana! Gee, but I wish he could have taken us with him. We've never been more than two hundred miles from home." "And I've never seen a mine in my life, much less a real mining camp." The Hardy boys looked at one another regretfully. They had just received a letter from their father, Fenton Hardy, an internationally famous detective, who had been called West but a fortnight previous on a mysterious mission. The letter gave the boys their first inkling of the nature of the case that had summoned their father from Bayport, on the Atlantic coast, to the mining country of Montana.