"That's so," agreed Ned. "But if they took her across country--"

"A different story," agreed Tom. "Come to think of it, maybe we'd better start to-night, Ned. We can make inquiries after dark as well as by daylight and get ready for an early morning hunt."

"Let's do it, then!" suggested his chum. "I'm ready. I'll send word that I'll not be home to-night."

"Good!" cried the young inventor. "We'll have an old-fashioned hunt after our enemies, Ned!"

"And don't leave me out!" begged Mr. Damon. Hurried preparations were made for the night trip. Tom ordered out one of his speediest, though not largest, automobiles, and told his helper to get the Hawk ready, to have her so she could start at a moment's notice if needed.

"You're not going in her, are you, Tom?" asked Ned.

"I may need her to-morrow for daylight hunting. If the tank's hidden somewhere, I can spot her from above more easily than from the ground.

So if we get any trace of my machine, I can phone in and have the aeroplane brought to me."

"That's a good idea!"

Inquiry at the shop where the tank had been built and kept disclosed the fact that, in addition to Koku, three of Tom's men had gone in her to help manage the machine under the direction of the man who bore the forged note. That he was one of the plotters not hitherto observed by either Ned or Tom seemed certain.

"And they took Koku and some of the men merely to make it look natural and as if it were all right," Tom said. "Naturally that deceived my father, who thought, of course, that I was waiting for the machine.

Well, it was a slick trick, Ned, but we may fool them yet."

"I hope so, Tom."

Night had fully fallen when Tom, Ned, and Mr. Damon started away in the touring car.

Out onto the road rolled the automobile. During the little daylight that had remained after his arrival at home and following the discovery of the loss of the tank Tom and Ned had traced it, by the marks of the big steel caterpillar belts, to the main road. It had gone along that some distance, just how far could not be said.

"But by using the searchlight of the auto we can trace her as long as they keep her on the road," said Tom. "After that we'll have to trust to luck, and to what inquiries we can make."

The touring car carried a powerful lamp, and by its gleams it was easy to trace for a time the progress of the ponderous tank. There was no need to make inquiries of persons living along the way, though once or twice Tom did get out to ask, confirming the fact that the big machine had rumbled past in a direction away from the Swift home.

"I had an idea they might have doubled on their tracks for a time, and backed her up just to fool us," Tom said. "They might do that, keeping her in the same tracks."

But this, evidently, had not been done, and the tank was making good speed away from the Swift house. They kept up the search until about midnight, and then a heavy rain began just before they reached a point where several roads branched.

"Luck's with them!" exclaimed Tom. "This will wash away the marks, and we'll have to go it blind. Might as well put up here for the night," he added, as they came to a village hotel.

It was evident that little more could be done in the rain and darkness, and there was danger of over-running the trail of the tank if they kept on. So they turned in at the hotel and got what little rest they could in their anxious state of minds.

Tom tried to be cheerful and to look for the best, but it was hard work. The tank was his pet invention, and, moreover, that her secrets should fall into the hands of the enemy and be used for Germany and against the United States eventually, made the young inventor feel that everything was going wrong.

The rain kept up all night, and this would make it correspondingly hard for them to pick up the trail in the morning.

"The only thing we can do is to make inquiries," decided Tom.

"Fortunately, the tank can't easily be hidden."

They started off after an early breakfast. The roads were so muddy and wet that traveling was difficult and dangerous for the automobile, and they were disappointed in finding no one who had seen or heard the tank pa.s.s up to a point not far from the hotel where they had stayed overnight. From then on the big machine seemed to have disappeared.

"I know what they've done," Tom said, when noon came and they had found no trace of the ponderous war machine. "They've left the road and taken her cross country, and we can't find the spot where they did this because the rain has washed out the marks. Well, there's only one thing left to do."

"What's that?" asked Ned.

"Get the Hawk! In that we can look down and over a big extent of country. That's what I'll do--I'll phone for the airship. The rain is stopping, I think."

The rain did cease by the time one of Tom's men brought the speedy aircraft to the place named by the young inventor in his telephone message. There were still several hours of daylight left, and Tom counted on them to allow him to rise in the air and look down on the tanks possible hiding place.

"One thing's sure," he told Ned: "I know the limit of her speed, and she can't be farther off than at some place within a circle of about one hundred and twenty-five miles from my house. And it's in the direction we're in. So if I circle around up above, I may spot her."

"I hope so," murmured Ned.

It was arranged that Mr. Damon should take the automobile back, with Tom's mechanician in it, and Tom and Ned would scout around in the aircraft, which carried only two.

"You ought to have a machine gun with you, Tom, if you plan to attack those fellows to get back the tank," Ned said.

"Oh, I don't imagine I'll need it," he said. "Anyhow, a machine gun wouldn't be of much effect against the tank. And they can't fire on us, for there wasn't any ammunition for the guns in Tank A, unless they got some of their own, and I hardly believe they'd do that. I'll take a chance, anyhow."

And so the search from the air began. It was disappointing at first.

Around and around circled Tom and Ned, their eyes peering eagerly down from the heights for a sight of the tank, possibly hidden in some little-known ravine or gully.

Back and forth, like a speck in the sky, Tom guided the Hawk, while Ned took observation after observation with the binoculars.

At last, when the low-sinking sun gave warning that night would soon be upon them, Ned's gla.s.ses picked up something on the ground far below that made him sit suddenly straighter in his seat.

"What is it?" asked Tom through the speaking apparatus, feeling the movement on the part of his chum.

"I see something down there, Tom," was the answer. "It doesn't look like the tank, and yet it doesn't look as a clump of trees and bushes ought to look. Have a peep yourself. It's just beyond that river, against the side of the hill--a lonesome place, too."

Tom took the gla.s.ses while Ned a.s.sumed control of the Hawk, there being a dual system for operating and steering her.

No sooner had the young inventor got the focus on what Ned had indicated than he gave a cry.

"What is it?" asked the young bank clerk.

"Camouflaged!" cried Tom, and without stopping to explain what he meant, he handed the binoculars back to Ned and began to guide the Hawk down toward the earth at high speed.

Chapter XXV

Foiled

"Is it really Tank A, Tom?" cried Ned, through the tube, as soon as he became aware of his companion's intention. "Are you sure?"

"That's the girl, and just where you spotted her with the gla.s.ses--in that clump of bushes. But they've daubed her with green and brown paint--camouflaged her, so to speak--until she looks like part of the landscape. What made you suspicious of that particular place?"

"The green was such a bright one in contrast to the rest of the foliage around it.',