"Well, it certainly was from here they pushed off their boat," declared Grace, walking down toward the edge of the water. "See, there are the marks of the keel in the sand."
That was true enough, as all the girls could see. The black box had been buried in the sand directly back from the point where the men had made their departure.
"There's another thing, too," added Betty. "That stick Amy has."
The other girls looked at it, Amy herself regarding it with rather curious eyes.
"It was stuck in the sand near the box," Amy said. "I worked it loose, pulled it up, and used it as a shovel."
"Exactly what it might have been intended for," spoke Betty, who let a little note of exultation creep into her voice. "At least, that was one of the purposes for which it was intended."
"And what was the other?" Mollie asked, as she put back a stray lock of her dark hair, for the wind had blown it about.
"As a mark," said Betty.
"A mark!" exclaimed Amy.
"Yes," went on Betty. "The men who hid the box put the stake in the sand so they could find their treasure again."