“What they mean to do with us depends a heap on what they intend to do themselves,” he said dubiously. “It’s my idea that, right or wrong, the rascals now in control of this craft must have had some sort of idea that she was on a treasure hunt. In that case, I think it’s likely that they may have secured in some way information as to where the treasure is, and are going after it themselves.”
“Then I wonder what they will do with us?” insisted Tom.
“By the grinning gondoliers of Granada, you’ve got me stuck. Maroon us, maybe, on some island, or——”
“Hullo! We’re moving!” cried Jack suddenly.
A perceptible vibration and hum ran through the yacht’s frame as her engines began to revolve. There was a port-hole in the cabin in which the boys were confined and Jack thrust his head out. But he could see no signs of the Wondership. Instead, through the rain which was now falling fast on a sullen, heaving sea, he could perceive, dimly, the distant coast line slipping by.
It was at this juncture that an odd sound came on the wall of the cabin.
“Somebody’s tapping!” exclaimed Tom, the first to solve the mystery.
“Sure enough,” rejoined Dick; “maybe it is your father. They may have put him in next door.”
“Hark!” exclaimed Jack suddenly. “Listen to those taps. Don’t you notice something odd about them?”
They listened in silence for a few minutes. Above the throbbing of the screw and the rush of water along the moving vessel’s side they could catch the odd rhythm of the taps being delivered on the cabin wall.