"Do you suppose they've all left the submarine?" whispered Gif presently. With the intense silence prevailing, they felt that they must be very cautious in making any noise.

"That's hard to say," answered Jack, with a shrug of his shoulders.

"It looks so to me," put in Fred. "I don't believe any of those fellows would care to stay down here unless it was necessary. They have stopped all the engines and things like that. I guess those electric lights are burning simply from a storage battery."

The three cadets waited for another ten minutes, and then, as no one appeared, and as the submarine seemed to be deserted, they stole forward cautiously, all anxious to get a closer look at the U-boat.

"If we could only throw a chain around the propellers, or something like that, maybe it would keep them from getting away if they tried to run for it," said the young captain.

"We'll look around and see what we can do, anyway," answered his cousin.

"There are plenty of chains around," put in Gif. "Those are what made the awful clanking sounds we heard."

Step by step the three cadets came up until they were at the spot where the Germans had set up their repair plant. Some of the things they had been working upon were still lying about, but other parts had been taken aboard the submarine.

"I guess they have all gone," said Jack, after a look around. "I'm going aboard that craft and take a peep at her."

The others were also anxious to do this, and all three were soon across the gangplank which led to the open hatch of the U-boat. They gazed down this hatch with some awe, and discovered that several electric lights had been left turned on below. A steel ladder ran down into the interior of the submersible.

"What do you say--shall we go below?" questioned Jack.

"I'm willing if you are," answered his cousin.

"And so am I," added Gif. "I don't believe there is any one around."

"Well, we'll take a chance," answered the young captain. "If there is any alarm, we'll have to run for it."

"Yes, and we may have to fight for it," added Fred.

Jack went down the ladder quickly, followed by the others. They now found themselves in what might be termed the main room of the submarine. Beyond were several other compartments, including one where was located much of the machinery which ran the undersea boat.

"It's a good deal like being downstairs on a small warship," declared Fred. "See, there are staterooms and messrooms and everything else!"

"Well, I suppose they have to give the crew some comforts, they take such long, disagreeable trips," remarked Jack.

The three cadets wandered around in the interior of the submarine for over a quarter of an hour. They saw where a number of repairs were being made to the side of the U-boat and also to some of the machinery, and they also saw where some stores had been taken on board, boxes and barrels of various kinds.

"I guess they are stocking up for another cruise," remarked Gif.

"It must be quite a job to get all that stuff to this out-of-the-way place," said Jack.

"Yes, and to do it so secretly, too," added Fred.

"I think I see a way of making this boat stay here for a while, at least," remarked Jack. "It will be an easy matter to put some of that delicate machinery forward out of commission."

"Come on and do it!" cried his cousin quickly.

The three cadets were inspecting the machinery and wondering how they could damage it effectively with the least possible trouble, when there came a sudden interruption.

"What are you doing here?" came in a guttural German voice. "Hands up, or I will shoot you!" And, turning quickly, the three cadets found themselves confronted by a burly German, holding in each hand a pistol.

CHAPTER XXVIII

THE CABIN IN THE WOODS

It was a comparatively easy matter for the twins and Spouter to get out of the cavern by the way they had entered. It was, however, not so easy for them to climb up the face of the cliff fronting that portion of Barlight Bay.

"Some climb, believe me!" panted Spouter, when they had reached a spot where going was easier.

"I came pretty near slipping and breaking my neck at one point," said Randy. "I don't believe those Germans ever use that entrance, do you?"

"Not very often," answered his twin.

The three cadets had reached the woods at a point which was new to them, being almost a mile from the other cliff, where they had had the outing with the girls. Between the two points there was a split in the land, and here the waters from the bay dashed in over a long series of jagged rocks.

"We can't cross there," remarked Randy, when they had reached the brink of this split. "We'll have to go back into the woods and go around."

It was now about five o'clock in the afternoon, and the tramping and climbing had tired all of the boys, yet they set off as rapidly as possible, feeling that it would be best to make a report to Captain Dale as soon as possible.

"I wish we had some trail to go by," remarked Randy, after they had been walking for at least half an hour. "I begin to think we are not moving in the right direction."

"I've been trying to guide myself by the sun," answered Spouter. "Just the same, I don't believe we are headed exactly for the camp."

"I've got to go a bit slower," sighed Andy, who for once was by no means light-hearted. "Both of my feet are beginning to hurt from all that climbing over the rocks. I came pretty close to twisting my ankle this afternoon, and it has been paining ever since."

Another half hour went by, and then, as the declining sun began to cast long shadows through the trees of the forest, the cadets looked at each other in alarm. The same thought had come into the minds of each of them.

"It looks as if we were lost," said Randy laconically. "How about it?"

"Oh, as the Indian said, we're not lost," responded Andy, with a faint smile. "It's only the camp that has gone astray."

"This is no time for joking," said Spouter coldly. "We've got to get back to camp, and do it just as fast as we can!"

"All right then, Spouter, show us the way," answered Andy readily.

"That's something I'm not so sure of," was the slow reply. "Which direction do you think it is in?"

The matter was talked over for several minutes, and finally the cadets moved off once more, this time at an acute angle to the direction they had before pursued. They went forward for perhaps a quarter of a mile, and then, much to their surprise, suddenly came out upon a well-defined wagon road.

"Well, what do you know about this!" cried Randy in astonishment.

"Where do you suppose this road leads to?" questioned his brother.

At this Randy shook his head, and Spouter did likewise. They could see the tracks of a horse and wagon in the road, and also the marks of automobile tires.