“We’re only guessing, anyway,” said Jack. “And there’s nothing to tell us whether we’re anywhere near the truth or not. All the same, I’m glad I slept on board, or I don’t know what might have happened. And here’s another thing. I’m going to sleep on board to-morrow night, too, and every other night, for a while. You can’t sit on the deck of the sloop all night, Cap’n Crumbie, and if some one wasn’t right on the spot every minute I believe this mysterious chap would get away with her.”

“I’m going to sleep on board, too,” said George.

“All right,” agreed the watchman. “’Tain’t such a bad idea, at that; only you want to keep your light going all the time. Not that you’ll catch anybody that way, but you’ll be safest.”

The lantern in the cabin had now been lighted, and the boys returned to their bunks, as there seemed no likelihood of any further excitement that night.

At dawn the skipper went on deck, and looked around as though half expecting to find evidence of the previous night’s encounter. Everything on the sloop was just as he had left it the previous afternoon after his last run across the ferry. Not even—

Suddenly the boy came to a standstill and stared down, his brows knit. Then he began to chuckle softly, and returned to the cabin.

“George, ahoy!” he said. “Wake up, lazy, and come out! I’ve something to show you.”

The mate opened his eyes and stretched.

“What’s up now?” he asked, yawning.

“I want to offer you my compliments,” said Jack.