"Did you let them know that you were coming?"
"Why, no, we didn't whistle."
"Then I don't see that you have any one to blame but yourselves," said Mr. Button tartly. "It's just as I said."
"But we're not so sure that it was an accident," persisted Fred.
"No," laughed Mr. Button. "I suppose you think that other boat was hiding behind the rock ready to jump out at you the way a pickerel starts for a minnow."
"If that was the only thing," explained Fred, "we might agree with you. But the trouble is that we're afraid somebody wants to injure the Black Growler."
"Why?" demanded Mr. Button, turning abruptly upon the boys as he spoke.
"To put her out of the race."
For a moment Mr. Button stared blankly at his grandson and then said quietly, "Don't you believe it. We don't have that kind of people around here. I shall have to write your father that you were to blame."
"And I'll write him and tell him all about it," said Fred angrily.