The old man was still digging away, but he had moved his position and was now deeper in the clump of trees.
"I'm sure he's after pirate gold!" exclaimed Sammy, in a whisper, for he knew sounds carry very distinctly over water, and he did not want the digging man to hear him.
"He's after something, right enough," agreed Frank. "What it is we can find out later."
"There's a boat, anyhow," put in Bob, pointing to one partly hidden under some brush and seaweed not far from the shore.
"That's right!" cried Sammy. "That shows he came from some other part of the Cove. We'll follow him!"
But, for the present, the man did not show any sign of being about to leave the clump of trees. He was digging away, paying no attention to anything around him, save to glance up now and then. If he saw the boys, as he must have done, he gave no sign.
Bob and his two chums, now that they were where they wanted to get, again threw the anchor overboard, and resumed their crabbing. But luck was not so good here, the boat being too near shore. However, they wanted an excuse for remaining near the man, and this gave them one.
"Here he comes!" suddenly exclaimed Sammy, as he wound up his crab line for future use. "Get ready now, boys."
The others looked up. Coming down toward the beach was the strange old man. Over his shoulder were a pick and a shovel, and in one hand he carried a square wooden box, with a strap for a handle.
"What do you s'pose he has that for?" asked Frank.