"DiD you hear that?" asked Tom Swift of his companion.

"Hear it? Bless my ear drums, I should say I did hear it! Some one is in trouble, Tom. Caught in a bog, most likely, the same as that spy chap who was at your place. That's it--caught in a bog!"

"There isn't any bog or swamp around here, Mr. Damon. If there was I shouldn't have tried a landing. No, it's something else besides that. Hark!"

Again the cry sounded, seeming to come from a point behind the landing place of the silent airship. It was clear and distinct:

"Help! Help! They are--"

The voice seemed to die away in a gurgle, as though the person's mouth had been covered quickly.

"He's sinking, Tom! He's sinking!" cried Mr. Damon. "I once heard a man who almost drowned cry out, and it sounded exactly like that!"

"But there isn't any water around here for any one to drown in," declared Tom. "It's a big, dry meadow. I know where we are."

"Then what is it?"

"I don't know, but we're going to find out. Some one attacked by some one else--or something, I should say," ventured the young inventor.

"Something! do you mean a wild beast, Tom?"

"No, for there aren't any of those here any more than there is water. Though it may be that some farmer's bull or a savage dog has got loose and has attacked some traveler. But, in that case I think we would hear bellows or barks, and all I heard was a cry for help."

"The same with me, Tom. Let's investigate;"

"That's what I intend doing. Come on. The airship will be all right until we come back."

"Better take a light--hadn't you? It's dark, even if the moon does show now and then," suggested Mr. Damon.

"Guess you are right," agreed Tom. Aboard his airship there were several small but powerful portable electric lights, and after securing one of these Tom and Mr. Damon started for the spot whence the call for help had come. As they walked along, their feet making no noise on the soft turf, they listened intently for a repetition of the call for aid.

"I don't hear anything," said Tom, after a bit.

"Nor I," added Mr. Damon. "We don't know exactly which way to go, Tom."

"That's right. Guess we'd better give him a hail; whoever it is."

Tom came to a halt, and raising his voice to a shout called:

"Hello there! What's the matter? We'll help you if you can tell us which way to come!"

They both listened intently, but no voice answered them. At the same time, however, they were aware of a sound as of hurrying feet, and there seemed to be muttered imprecations not far away. Tom and Mr. Damon looked in the direction of the sound, and the young inventor flashed his light. But there was a clump of bushes and trees at that point and the electrical rays did not penetrate very far.

"Some one's over there!" exclaimed Tom in a whisper. "We'd better go and see what it is."

"All right," agreed Mr. Damon, and he, too, spoke in a low voice.

Why they did this when their previous talk had been in ordinary tones, and when Tom had shouted so loudly, they did not stop to reason about or explain just then. But later they both admitted that they whispered because they thought there was something wrong on foot--because they feared a crime was being committed and they wanted to surprise the perpetrators if they could.

And it was this fact of their whispering that enabled the two to hear something that, otherwise, they might not have heard. And this was the sound of some vehicle hurrying away--an automobile, if Tom was any judge. The cries for help had been succeeded by stifled vocal sounds, and these, in turn, by the noise of wheels on the ground.

"What does it all mean?" asked Mr. Damon in a whisper.

"I don't know," answered Tom, resolutely, "but we've got to find out. Come on

They advanced toward the dark clump of trees and low bushes. There was no need to be especially cautious in regard to being silent, as their feet made little, if any, sound on the deep grass. And, as Tom walked in advance, now and then flashing his light, Mr. Damon suddenly caught him by the coat.

"What is it?" asked the young inventor.

"Look! Just over the top of that hill, where the moon shines. Don't you see an automobile outlined?"

Tom looked quickly.

"I do," he answered. "There's a road from here, just the other side of those trees, to that hill. The auto must have gone that way. Well, there's no use in trying to follow it now. Whoever it was has gotten away."

"But they may have left some one behind, Tom. We'd better look in and around those trees."

"I suppose we had, but I don't believe we'll find anything. I can pretty nearly guess, now, what it was."

"What?" asked Mr. Damon.

"Well, some chauffeur was out for a ride in his employer's car without permission. He got here, had an accident--maybe some friends he took for a ride were hurt and they called for help. The chauffeur knew if there was any publicity he'd be blamed, and so he got away as quickly as he could. Guess the accident--if that's what it was--didn't amount to much, or they couldn't have run the car off. We've had our trouble for our pains."

"Well, maybe you're right, Tom Swift, butt all the same, I'd like to have a look among those trees," said Mr. Damon.

"Oh. we'll look, all right," assented Tom, "but I doubt if we find anything."

And he was right. They walked in and about the little grove, flashing the light at intervals, but beyond marks of auto wheels in the dust of the road, which was near the clump of maples, there was nothing to indicate what had happened.

"Though there was some sort of fracas," declared Tom. "Look where the dust is trampled down. There were several men here, perhaps skylarking, or perhaps it was a fight."

"Some one must have been hurt, or they wouldn't have cried for help," said Mr. Damon.

"Well, that's so. But perhaps it was some one not used to riding in autos, and he may have imagined the accident was worse than it was, and called for help involuntarily. There is no evidence of any serious accident having happened--no spots of blood, at any rate," and Tom laughed at his own grimness. "It was a new car, too, or at least one with new tires on."

"How do you know?" asked Mr. Damon.

"Tell by the plain marks of the rubber tread in the dust," was the answer. "Look," and Tom pointed to the wheel marks in the focus of his electric lamp. "It's a new tire, too, with square protuberances on the tread instead of the usual diamond or round ones. A new kind of tire, all right."

He and Mr. Damon remained for a few minutes looking about the place whence had come the calls for help, and then the eccentric man remarked:

"Well, as long as we can't do anything here, Tom, we might as well travel on; what do you say?"

"I agree with you. There isn't any use in staying. We'll get the Air Scout fixed up and travel back home. But this was something queer," mused Tom. "I hope it doesn't turn out later that a crime has been committed, and we didn't show enough gumption to prevent it."

"We couldn't prevent it. We heard the cries as soon as we landed."

"Yes, but if we had rushed over at once we might have caught the fellows. But I guess it was only a slight accident, and some one was more frightened than hurt. We'll have to let it go at that."

But the more he thought about it the more Tom Swift thought there was something queer in that weird cry for help on the lonely meadow in the darkness of the night.