"You seem to have lots of trouble with your boat, Andy," said Tom after a few moments of rather embarrassed silence.

"I do," admitted the owner of the Red Streak. "I've had bad luck ever since I got it, but usually I've been able to fix it by looking in the book. This time I can't find out what the trouble is, nor can any of the fellows. It stopped when we were out in the middle of the lake and we had to row. I'm sick of motor boating."

"Suppose I fix it for you?" went on Tom.

"If you do, I'll pay you well."

"I wouldn't do it for pay---not the kind you mean," continued the young inventor.

"What do you mean then?" and Andy's face, that had lighted up, became glum again.

"Well, if I fix your boat for you, will you let me run it a little while?"

"You mean show me how to run it?"

"No, I mean take it myself. Look here, Andy, my boat's been stolen, and I thought you took it to get even with me. You say you didn't---"

"And I didn't touch it," interposed the squint-eyed lad quickly.

"All right, I believe you. But somebody stole it, and I think I know who."

"Who?" asked Sam Snedecker.

"Well, you wouldn't know if I told you, but I suspect some men with whom I had trouble before," and Tom referred to Happy Harry and his gang. "I think they have my boat on this lake, and I'd like to get another speedy craft to cruise about it and make a further search. How about it, Andy? If I fix your boat, will you let me take it to look for my boat?"

"Sure thing!" agreed the bully quickly, and his voice for once was friendly toward Tom. "Fix the engine so it will run, and you can use the Red Streak as long as you like."

"Oh, I probably wouldn't want it very long. I could cover the lake in about three days, and I hope by that time I could locate the thieves. Is it a bargain?"

"Sure," agreed Andy again, and Tom got into the motor-boat to look at the engine. He found that it would require some time to adjust it properly and that it would be necessary to take the motor apart.

"I think I'd better tow you to my dock," the young inventor said to Andy. "I can use some tools from the shop then, and by to- night I'll have the Red Streak in running order."

The breeze was in the right quarter, fortunately, and with the motor-boat dragging behind, the Arrow's owner put the nose of the sailing craft toward his home dock.

When Tom reached his house he found that Mrs. Baggert had received another telephone message from Mr. Swift, inquiring why his son had not returned to Sandport.

"He says if you don't come back by to-morrow," repeated the housekeeper, "that he'll come home by train. He's getting anxious, I believe."

"Shouldn't wonder," admitted Tom. "But I want him to stay there. The change will do him good. I'll soon have my boat back, now that I can go about the lake swiftly, and then I'll join him. I'll tell him to be patient."

Tom talked with his father at some length, assuring him that everything was well at the Shopton house and promising to soon be with him. Then the young inventor began work on the motor of the Red Streak. He found it quite a job and had to call on Mr. Jackson to help him, for one of the pistons had to be repaired and a number of adjustments made to the cylinders.

But that night the motor was fully mended and placed back in the boat. It was in better shape than it had been since Andy had purchased the craft.

"There," remarked Tom, "now I'm ready to hunt for those scoundrels. Will you leave your boat at my dock to-night, Andy?"

"Yes, so you can start out early in the morning. I'm not going."

"Why not?" demanded Tom quickly.

"Well---er---you see I've had enough of motoring for a while," explained Andy. "Besides, I don't believe my mother would like me to go out on a chase after thieves. If we had to shoot I might hit one of them, and---"

"Oh, I see," answered Tom. "But I don't like to take your boat alone. Besides, I don't fancy there will be much shooting. I know I'm not going to take a gun. In fact, the one Mr. Duncan gave me is in the boat. All I want is to get the Arrow back."

"That's all right," went on Andy. "You take my boat and use it as long as you like. I'll rest up a few days. When you find your boat you can bring mine back."

Tom understood. He was just as glad not to have Andy accompany him in the chase, as he and the red-haired lad had never been good friends and probably never would be. So it would cause some embarrassment to be together in a boat all day. Then again Tom knew he could manage the Red Streak better alone, but, of course, he did not want to mention this when he asked for the loan of the craft. Andy's own suggestion, however, had solved the difficulty. Tom had an idea that Andy felt a little timid about going in pursuit of the thieves, but naturally it would not do to mention this, for the squint-eyed lad considered himself quite a fighter.

Early the next morning, alone in the Red Streak, Tom continued the search for his stolen boat. He started out from his home dock and mapped out a course that would take him well around the lake.

"I s'pose I could take a run to Sandport now," mused the youth as he shot in and out of the little bays, keeping watch for the Arrow. "But if I do dad will have to be told all about it, and, he'll worry. Then, too, he might want to accompany me, and I think I can manage this better alone, for the Red Streak will run faster with only one in. I ought to wind up this search in two days, if my boat is still on the lake. And if those scoundrels have sunk her I'll make them pay for it."

On shot the speedy motor-boat, in and out along the winding shoreline, with the lad in the bow at the steering-wheel peering with eager eyes into every nook and corner where his craft might be hidden.