Tom Swift and His Undersea Search, Or, The Treasure on the Floor of the Atlantic

Times have changed. The Great War is over and money is getting hard to come by. Mr. Damon shows up with a new friend, who promises wealth from the bottom of the sea. Tom reluctantly agrees to join the search for the sunken steamship SS Pandora and a million dollars in gold coin. Like the Greek legend, the strong box on the Pandora contains much more and less than the treasure seekers expected.