“He gave me this letter, some years ago,” he said. “It just tells me that he’s going to leave me the gold as my share, being the only survivor that kept the agreement Here’s the letter.”
Bob eagerly read it. As Hiram had said, it contained just that information, and nothing more. But at the end of the letter were these words:
“Don’t destroy the envelope.”
“Now what did he mean by that?” asked Bob, puzzled. “Is there anything else in the envelope? Let’s look, Harry.”
He took from his chum the envelope that had contained the letter. Looking inside Bob gave a cry of surprise and exultation.
“I’ve found it! I’ve got it!” he cried “What?” asked his chums.
“The key to the cipher! Look!”
With his knife Bob slit the envelope down each end. It was of thick, manila paper, and on the inside of what was the front there were marked off in black ink a number of small oblong spaces, placed here and there irregularly.
“I don’t see how that’s going to help any,” observed Ned.
“You don’t? Just wait a minute!” cried Bob.