Will had hastily unfastened his camera, and held it in his hands as he spoke.

“All right, then.  Come on, boys!”

With these words, Frank led the way into the woods.

“Sure the sound came from this direction?” asked Bluff.

“That was my impression.  What do you say, Jerry?” and Frank turned to the chum on whose knowledge of woodcraft he felt he could rely.

“Straight in there.  You’re heading all right, Frank,” he replied.

“How far did it seem to be?” went on the leader.

“That is hard to say.  The man may have been weakened from loss of blood.  If he was shouting, then it may have been several hundred yards, perhaps a quarter of a mile off; but I think we’ll come across him closer than that.”

“I agree with you, Jerry,” said Frank, stopping short.

“What did you hear?” demanded the other, for Frank had bent his head, and seemed to be listening over his shoulder.

“I don’t know.  Perhaps it was a bush springing back into place after our passage.  But suppose we shout occasionally?  It may encourage the poor fellow, and besides, guide us to where he lies,” returned Frank, once more pushing on.

Accordingly they lifted up their voices and gave a series of calls.

“Why doesn’t he answer us?” asked Will, astonished when only the echoes came back from the surrounding forest.

Frank stopped in his tracks.

“Can he have fainted from loss of blood?” said Bluff, still having in mind a picture of a woodsman who had severed an artery by a misblow of his ax.

“There’s Frank listening again, and he seems to be paying more attention to our rear than ahead,” remarked Will, puzzled.

“I bet you he thinks somebody is playing us for a lot of fools; that there isn’t any one hurt, or in need of help at all.  What’s that?”

The distinct and well-known “popping” of a motor was heard.

“It’s a trick, fellows!  Somebody is meddling with our machines!  Back to the road!” shouted Jerry, turning and plunging through the under-brush recklessly.

A wild scramble followed.  The four chums were so excited, and filled with a determination to stop the unknown miscreants from making way with their machines, that they gave little heed to their steps.  The consequence was that more than once a collision with a tree ensued, and various bumps afterward gave mute evidence as to the reckless manner of their chase.

“There’s two of ’em!” shrieked Will from the rear, as he caught the sound of a second series of erratic poppings.

Evidently those who were meddling with the motorcycles did not have a thorough knowledge of how to work the same, for the sounds would suddenly cease and then start up again.

“Oh! don’t I wish they’d just take headers over some nice fat root!” gasped the perspiring Will, still hugging his precious camera to his heart as he followed in Frank’s wake.