"And we haven't solved the mystery," said Bert in a low voice to
Harry. "But we will to-night, all right."
"We sure will," agreed the boy from the country.
The Bobbsey twins stayed up rather later that night than usual. Mr. Bobbsey did not find a good anchorage for the boat for some time, as he wanted to get in a safe place. It looked as though there might be a storm before morning, and he did not want to drift away again. Then, too, he wanted to get nearer to the waterfall, so they could reach it early the next morning and look at it more closely.
So the motor was kept in action by Captain White until after supper, and finally the Bluebird came to rest not far from the waterfall. Then Bert and Nan, with Dorothy and Harry were so interested in listening to Mr. Bobbsey tell stories about waterfalls, and what caused them, that the older twins and their cousins did not get to bed until nearly ten o'clock, whereas nine was the usual hour.
Of course Flossie and Freddie "turned in," as sailors say, about eight o'clock, for their little eyes would not stay open any longer.
"We'll wake up as soon as my father and mother are asleep," said Bert to Harry, as they went to their rooms, which were adjoining ones. "Then we'll take turns watching that closet."
"Sure," agreed Harry. "Whoever wakes up first, will call the other."
To this Bert agreed, but the truth of it was that neither of them awakened until morning. Whether it was that they were too tired, or slept later than usual, they could not tell. But it was broad daylight, when they sat up in their beds, or "bunks," as beds are called on ships.
"I thought you were going to call me," said Bert to his cousin.
"And I thought you were going to call ME," laughed the boy from the country.