"Oh, then you are sure it is treasure," Mollie returned.
"Well, we might as well think that as anything else—until we get the box open and find it full of—sand!" declared Betty, laughing.
"Oh, let's open it now!" cried Grace, impulsively. "I'm just dying to see what's in it. Please let's open it now."
"Perhaps we have no right," objected Amy.
"Why, of course we have," insisted Grace, making "big eyes" at Amy. "We found it. Can't we open it, Betty?"
But there was a very good reason why the girls could not open the box—at least then and there.
CHAPTER XI
THE CIPHER
"Locked!" exclaimed Betty, laconically, when she had tried the cover of the box.