Greatly interested in what was about to take place, and not a little suspicious, our friends stood on the bank of the river and watched the motor boat returning. As it reached a little dock in front of the hut, the man who had waved the red flag of warning came out, and talked rapidly to those in the power craft. At the same time he pointed occasionally to Tom, Ned and the government agent.

"This is getting interesting," remarked Mr. Whitford. "We may have accidentally stumbled on something important Tom."

"See, they're signalling to the steamer now," spoke Ned, and, as he said this, his companions looked, and noted the man from the hut waving a white flag, in a peculiar manner. His signals were answered by those on the vessel anchored out in the stream, and, a little later, black smoke could be seen pouring from her funnel.

"Looks as if they were getting ready to leave," spoke Tom.

"Yes, we seem to have started things moving around here," observed Ned.

"Or else we have prevented from moving," remarked the custom agent.

"What do you mean?" Tom wanted to know.

"I mean that these men were evidently going to do something just as we arrived, and spoiled their plans. I would say they were going to land goods from that schooner. Now the are not."

"What kind of goods?" asked Ned.

"Well, of course I'm not sure, but I should say smuggled goods."

"The smugglers!" cried Tom. "Why, they can't be smugglers, for we are on Canadian territory. The river isn't the dividing line between the Dominion and the United States at this point. The St. Lawrence lies wholly in Canada here, and the men have a right to land any goods they want to, dutiable or not."

"That's just it." put in Mr. Whitford. "They have the right, but they are afraid to exercise it, and that's what makes me suspicious. If they were doing a straight business they wouldn't be afraid, no matter who saw them. They evidently recognize us, by description, if by no other means, and they know we are after smugglers. That's why they stopped the brining of goods from that vessel to shore. They want to wait until we are gone."

"But we couldn't stop them from landing goods, even if they know we are working for Uncle Sam," declared Tom.

"That's very true, but it is evidently their intention, not only to land goods here, which they have a perfect right to do, but to send them into the United States, which they have not a right to do without paying the duty."

"Then you really think they are the smugglers?" asked Ned.

"I'm pretty sure of it. I think we have stumbled on one of the places where the goods are landed, and where they are loaded into the airships. This is the best luck we could have, and it more than makes up for not catching the rascals last night. Now we know where to get on their trail."

"If they don't change the place," observed Tom.

"Oh, of course, we've got to take that chance."

"Here's one of them coming over to speak to us, I guess," remarked Tom in a low voice, as he observed the man, who had waved the flag approaching. There was no doubt of his intention for, as soon as he came within talking distance, the stranger called out:

"What are you fellows doing here?"

"Looking at the river," replied Mr. Whitford, calmly.

"Well, you'd better find some other place for a view. This is private property, and we don't like trespassers. Get a move on--get out!"

"Are we doing any harm?" asked the agent.

"I didn't say you were. This is our land, and we don't like strangers snooping around. That's all."

"Particularly when you are going to land some goods."

"What do you mean?" gasped the man.

"I guess you know well enough," was Mr. Whitford's reply.

The man suddenly turned, and gave a shrill whistle. Instantly, from the hut, came several men who had been in the motor boat. One or two of them had weapons.

"I guess you'd better go now," said the first man sharply. "You're not in the United States now, you know."

"It's easy to see that, by the politeness of the residents of this section," put in Tom.

"None of your back talk! Get away from here!" cried the man. "If you don't go peaceably--"

"Oh, we're going," interposed Mr. Whitford calmly. "But that isn't saying we won't come back. Come on, boys. We'll get over on Uncle Sam's territory."

The group of men stood silently watching them, as they filed back through the woods.

"What do you make of it?" asked Tom of the agent.

"I'm positive that I'm right, and that they're the smugglers. But I can't do anything on this side of the line. If ever I can catch them across the border, though, there'll be a different story to tell."

"What had we better do?" inquired Ned.

"Go back to our airship, and leave for Logansville. We don't need to land until night, though, but we can make a slow trip. Is the gas machine all right again, Tom?"

"Practically so. If that hadn't gone back on me we would have had those fellows captured by this time."

"Never mind. We did our best."

It did not take Tom and his chum long to complete the repairs, and soon they arose in the air.

"Let's take a flight over where those fellows are, just to show them what we can do," proposed Ned, and Tom and Mr. Whitford agreed to it. Soon they were circling over the hut. The launch was just starting out again, when a cry from the man who seemed to be a sort of guard, drew the attention of his confederates to the noiseless airship.

Once more the launch was turned about, and sent back to shore, while those in it shook their fists at Tom and his friends.

"We can play tag with 'em up here!" chuckled Ned.

"There's the small vessel that pulled up anchor a while ago," remarked Mr. Whitford, pointing to the vessel which had steamed around a wooded point. "They thought we had gone for good, and they were getting ready to land the stuff. Well, we'll know where to head for next time, when we watch for the smugglers at night."

Realizing that nothing more could be done, Tom sent his airship toward the camp, just outside of Loganville. But he did not land until after dark, when, making out the spot by means of the electric lights, which were set aglow automatically at dark, he descended.

"We won't try anything to-night," said Mr. Whitford. "I doubt if the smugglers will themselves, after their experience last night. I'll get into town, see some of my men, and come out here to-morrow night again."

Tom and Ned spent the following day in going carefully over the Falcon, making some slight repairs. The great searchlight was cleaned and adjusted, and then, as dusk came on once more Tom remarked:

"Well, we're ready for 'em any time Mr. Whitford is."

Hardly had he spoken than the tramp of horses' feet was heard coming along the bridle path through the woods, and a voice was heard to exclaim:

"There, now, I understand it perfectly! You don't need to say another word. I know it may be against the regulations, but I can fix that. I'm the busiest man in the world, but I just had to come up here and see Tom Swift. It's costing me a thousand dollars, but the money is well spent. Now don't interrupt me! I know what you're going to say! That you haven't time to bother with moving pictures. But you have! I must have some moving pictures of your chase after the smugglers. Now, don't speak to me, I know all about it. You can't tell me anything. I'll talk to Tom. Are we most there?"

"Yes, we're here," answered Mr. Whitford's voice, and Tom fancied the government agent was a bit puzzled by his strange companion.

"Bless my shoe string!" gasped Mr. Damon.

"Him picture man!" cried Koku.

"Mr. Period!" exclaimed Tom. "I wonder what he is doing here?" and the next moment the excitable little man, for whom Tom had run so many risks getting marvelous moving pictures, with the wizard camera, entered the clearing where the airship was anchored.