The three looked at each other. For a moment they could not understand, and then, as they stood there, the meaning came to them.

"The smugglers!" whispered Tom.

"Of course!" agreed Mr. Damon. "And they must have taken him for you, Tom, for he had on your coat and cap. What can they have done with him?"

"Taken him away, that's evident," spoke Tom. "Let's look around, and see if we can find him."

They looked, but to no purpose. Ned had disappeared. There were the signs of a struggle, the fish rod was broken in several places, as if Ned had used it as a club, and the ground was torn up.

"Bless my tin whistle!" cried Mr. Damon. "What shall we do?"

For a moment no one knew what to say, then, as they looked at each other in silence, a voice called:

"I say! What's up? What's the matter? Where are you all? Hey, Tom Swift!"

"It's Mr. Whitford!" cried Tom. "He's just in time." Then he called in louder tones:

"Here we are! In the woods by the trout brook! Come on over! Ned is gone!"

There was a commotion in the bushes, the trampling of a horse, and a moment later the government agent had joined the others.

"What's this?" he cried. "Ned gone? What do you mean?"

"He's missing. The smugglers have him, I'm afraid," explained Tom, and then he gave the details.

"It certainly looks so," agreed Mr. Whitford. "His wearing of your coat and cap fooled them. They must have spied out this camping place, and they were in hiding. When they saw Ned coming to fish they took him for you. Having failed in their attempt to damage the airship, they decided to get her captain. Probably they thought that if they did the Falcon could not be run, and they would be safe. But they got the wrong man."

"Then we must get Ned back at once!" cried Tom. "Come on, we'll start right away! Where do you think we can nab them, Mr. Whitford?"

"Wait a minute," suggested the government agent. He seemed in deep thought, and paced up and down. It was clear that a great question was confronting him.

"Well!" exclaimed Tom impatiently, "if we're going to get Ned we must start at once."

"Perhaps it would be best not to try to rescue Ned at once," said the custom house man after a pause.

"What!" cried Tom. "Not rescue Ned, my best chum?"

"Not at once," repeated Mr. Whitford. "Look here, Tom. I know it seems a hard thing to say, but perhaps if we proceed on our original plan, to hover over the border, and get on the trail of the smugglers, chasing them to where they land the goods in the United States, it will be best."

"And not rescue Ned?"

"We can best rescue him by catching the smugglers."

"Then you think--"

"That they have him with them--on board one of their airships very likely. If we get them we'll have Ned."

"Then we'll get 'em!" cried Tom with energy. "Come on back to the Falcon. We'll get ready for a big flight!"

"Yes, I think they'll make a desperate effort to-night," went on the agent. "They have a lot of goods ready to rush over the border, and the fact that they tried to capture you, shows that they are ready to pull off a big trick. I think if we can catch them to-night, it will put an end to their operations, and, at the same time, bring Ned back to us."

"Where do you think they will start to cross the line?" asked Tom.

"Near the place where we saw the man waving the flags. I have information to the effect that they have a store of valuable goods there. They imagine that they have the master of the airship, and the owner of the great searchlight in their power, and that they can not be molested, so they will be bold."

"But they'll soon find out that Ned isn't Tom," said Mr. Damon.

"No they won't! Not if it depends on Ned!" cried Tom. "Ned is game. He'll soon get wise to the fact that they have taken him for me, and he'll carry on the deception. None of the smugglers know me intimately."

"Unless Andy Foger should be with them," suggested Mr. Damon.

"Oh, Ned can fool Andy any day. Come on, Mr. Whitford. We'll get the smugglers to-night, spoil their game, and rescue Ned. Somehow, I feel that we're going to succeed."

"Bless my tin dishpan!" cried Mr. Damon. "I hope we do."

Slowly, and with no very cheerful hearts, they filed away from the scene of Ned's capture. In spite of the fact that they did not think he would be harshly treated, they worried about him, Tom especially.

A hasty supper was eaten, and then, Tom, having seen that everything aboard the ship was in good order, sent her aloft on what he hoped would be the last chase after the smugglers. He decided to have Mr. Damon steer the craft, as this was comparatively easy, once she was started on her course, while the young inventor would manage the searchlight, and start the automatic wizard camera, in case there was anything to photograph.

Up and up went the Falcon, and soon she was making her way toward the St. Regis Indian reservation, near which it was expected the smugglers would start. Tom put out every light, as he wanted to remain in darkness, until he could see a moving glow in the sky that would tell him of a rival airship on the wing.

It did not take them long to reach the desired spot, and they hovered in the air over it, every one with tense nerves, waiting for what would happen next.

Tom did not want to show his searchlight just yet, as he feared the gleam of it might stop the operations of the smugglers. So he waited in dark-ness, approaching close to the earth in his noiseless ship several times, and endeavoring to see something through the powerful night glasses.

Suddenly, from below them, came a subdued throb and hum of a motor.

"There they are!" exclaimed Mr. Damon.

"I think so," agreed Tom. He looked below. He saw two flickering lights, rather far apart. Mr. Whitford observed them at the same moment.

"There are two of them!" exclaimed the agent, "Two airships, Tom!"

"So I see. Koku, get out my electric rifle. We can't chase two, if they separate, so I may have to stop one. It's best to be prepared. I'm going to follow them in the dark, until they get over the border, and then I'll turn on the light and the camera. Then it will be a race to the finish."

The twin lights came nearer. Tom stood with his mouth to the signal tube that communicated with Mr. Damon in the pilot house. From a side window he watched the smugglers' airships. They shot upward and then came on straight ahead, to pass to one side of him. Now they were past. Tom started the wizard camera.

"Half speed ahead!" the young inventor signalled, and the Falcon shot forward. The night race was on.