There was enough, as Frank soon discovered, and when he came up on deck again he found Andy leaning against the tiller and peering at the distant vessel through the binoculars.

"Can you make out anything?" he asked.

"No, I can see several men aboard, but I don't notice our mysterious friend."

"Do they seem to be paying any attention to us?"

"Not a bit. Guess they don't even know we are here. I don't believe we are going to catch up to them, though."

"Oh, yes we are. The _Gull_ is plenty fast, and they are handicapped by dragging that motor boat in the water. It must be partly filled, as it sets so far down, and that makes it all the harder to tow. We're gaining on them."

"Not so's you could notice it."

"Oh, well, we've got all day, and grub enough for another night. I'm not going to give up this chase until I have to, or until I've solved the mystery."

"And I'm with you."

There is not much excitement in a sailing race, as the boys very soon found out. There was nothing they could do, which would have been the case in a motor craft, to add to their speed. All they could do was to sit and let the wind carry them. And they were glad to see that the breeze was continually freshening.

"There'll be another gale before night, if this keeps up," predicted Frank.

"Let it," a.s.sented Andy. "The _Gull_ likes heavy weather, and we can stand it."

"Yes, but father and mother will be worried about us. If it comes on to blow too hard we'll have to turn back."

"And let that man get away?"

"There'd be no help for it. But we haven't turned back yet, and now his craft ought to be easy to trace."

Once more they looked through the gla.s.s at the vessel ahead of them.

They could see sailors moving about on deck, but that was all. No sign of the tall dark man was visible.

"Perhaps he isn't aboard," suggested Andy.

"It can't be helped," answered his brother. "We want the motor boat almost as much as we want the man, and we can't take our choice I'm afraid. But we are certainly creeping up on them."

This was true, for while two miles had at first separated the vessels, the distance was now narrowed to a little less than a half mile, and the _Gull_ was sailing better than was her rival.

"What are you going to do when you get within hailing distance?" asked Andy, after a pause.

"I don't know--haven't exactly made up my mind," was the answer of the elder Racer lad. "But I'll have to soon."

Frank was giving all his attention to managing the _Gull_, so as to gain every foot. Andy went up forward now and then to report progress.

"Hey, Frank!" he suddenly called, "there's something doing on board."

"What makes you think so?"

"Why the whole crowd of them have come aft and are looking at us for all they're worth."

"Are they using gla.s.ses?"

"No--yes, they are too! A new man has come up on deck, and he's got a pair. He's training them on us."

"Good! That shows they're worried. Take our gla.s.ses and see what you can make out."

Andy looked long and earnestly. Then he let out a yell.

"It's him! It's that mysterious man!" he shouted. "He's excited, too, for he's making motions to the crew!"

"Good! Watch him carefully. We'll be up to them in about five minutes."

Andy watched. In a minute he gave another cry.

"What is it?" asked Frank.

"They're laying-to--waiting for us, I guess."

"They won't have long to wait," declared Frank grimly.

The _Gull_ was swiftly slipping through the water. In a little while it was almost abeam of the craft towing the mysterious motor boat.

Frank threw her head up into the wind, and, as he did so a voice from the other sailboat hailed him.

"_Gull_ ahoy! Are you trailing us?"

It was the mysterious man calling, and he was standing on the rail.

"Yes, we are," answered Frank boldly.

"Well, what do you want?"

"We want to find out who you are, what you have to do with a boy named Paul, why you have his motor boat in tow, and why you entered our house like a thief in the night."

"Hu! That's a lot of questions. And I suppose you think they'll be answered," commented the man, in sneering tones.

"I do," said Frank calmly. "Where are you going with that boat?"

"None of your business!" snapped the man. "And I want to tell you one thing more. You've got to quit trailing after us, too!"

"Suppose we refuse?" asked Andy.

"Then it will be the worse for you. Meldrick, just run that bra.s.s cannon over on this side."

A moment later the muzzle of a small bra.s.s gun was pointed menacingly at our heroes.

"There's my answer," went on the mysterious man. "If you persist in following us you'll be plugged below the water line. Now you go back where you came from, and keep away. Don't try to meddle with what doesn't concern you."

"This does concern us--or, rather a friend of ours," said Frank determinedly. "And what's more, we're going to swear out a warrant for your arrest for setting fire to our boat with a bale of hay."