"That's the best joke ever played on a bunch of fellows," cried Billy. "And you've won the wager fairly enough. You don't need to apologize for the ghosts. The trouble is we tried to play worse jokes on you, but you turned them on us every time. If we got you out of the lake it was by good luck, not because we were so awfully brave. I'll never brag about bravery after last night. And now good night. You folks are tired and want to go to bed. We'll see that you aren't disturbed this evening. You don't think of working your disappearing act to-night, do you?"
"No. We have had sufficient excitement for one day," answered Miss Elting laughingly. "We are going to invite you over to dinner soon, then we will have a happy good-bye party before we leave. By the way, boys, we are going ashore in the morning on a shopping trip. As all of us wish to go I am going to ask you if you will keep an eye on the 'Red Rover.' There is very little possibility that our enemy will visit it in broad daylight, still it is best to take proper precautions against further attacks."
"We'll be very glad to look out for the 'Red Rover' while you're away," responded George heartily. "That is if you can assure us that you won't try any new vanishing tricks."
"We give you our solemn promise," laughed Harriet. "The 'Red Rover' has played her last trick."
Harriet's laughing assurance, however, was destined to prove truer than she had dreamed. The next morning the girls rose early, and after a hasty breakfast went ashore to do their shopping, secure in the thought that the Tramp Club would keep an eye on the "Red Rover."
In the meantime the boys had posted a watch on the shore, in the person of Billy Gordon, who seated comfortably on the ground, his back against a big tree, glanced frequently out over the lake to where the "Red Rover" lay at anchor, her red sides glistening in the sun.
It was well towards noon when Billy rose from the ground and strolled lazily down to the beach. Suddenly his good-natured face took on a startled look as he stared anxiously toward the houseboat. A moment later he was running toward the tent at full speed.
"Fellows, come out here!" he shouted. "Hurry up!"
"What's the matter?" asked George Baker, hurrying out of the tent, the other members of the Tramp Club at his heels.
"Look!" gasped Billy, pointing toward the "Red Rover." "What do you make of that?"