ntly now, of course,
making, with the motor shut off, no more sound than a falling leaf.
Down to the soft, springy turf in the green meadow Tom guided the
machine. As it came to a stop, and he and Mr. Damon got out, there was
borne to their ears a wild cry:

"Help! Help!"

CHAPTER XIII

SOMETHING QUEER

"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.