Dave had been searching the hills with his binoculars for some time when he suddenly gave the glass to the ensign.

“What’s that tangle above the cliffs there?” he asked.

The ensign studied the cliffs for some time.  Then he touched a button with his foot and they turned silently shoreward.

“That’s it!” He said with an air of finality.

“What?” asked Dave eagerly.

“The wireless.”  Then the ensign explained to Dave the purpose of their journey.  They had been sent into the Arctic to locate a wireless station, supposed to be placed in the Aleutian Islands; a station run by radical propagandists, part of a world-federation, which proposed to wreck all organized society.  Had Dave realized that the missions of sub and airplane were alike he would have been startled.  As it was, his face took on a tense, expectant look, his cheeks burned hot with excitement.

The Doctor was called to the conning-tower.  After studying the contour of the island for some time, he said: 

“Their shack, built of rocks and driftwood logs, is at the base of the cliff.  That is good.  We will divide into two parties.  Four of us will go up the cliff and get above them, while four others will skirt the cliff and, under cover, await my signal.  Our supporting party will take ropes, rifles and a machine-gun.  I will go with the party to the top of the cliff.  We will carry only rifles and some special instruments of attack which I have stored in canvas sacks below.  Two men must remain on board.  Head in close to those rocks before us.  They are out of sight of the shack and there is ice stranded there—­a straggler will scarcely tell our craft from it.  I have no doubt there are a number of them and that they are hardy ruffians.  We must proceed with great care.

“Hark!” He put his hand to his ear.  “They are sending messages now.

“In the future,” continued the Doctor, as he handed Dave two strange-looking spheres, the size of a man’s head, “the work of sheriffs, policemen and other officers of the law is not going to be quite so hazardous.  When a criminal runs amuck, he will not kill a half-score of brave men before he is captured.  The officers of the law will do what we will soon be doing, and a child can do the rest.  Only,” he continued, “watch your step going up that hill.  It doesn’t take much of a bump to get one of these funny little balls excited.”

Dave had been detailed to assist the Doctor.  Ensign Blake would lead the supporting party around the cliff, there to await the Doctor’s signals.

Besides the sack in which Dave carried the large spheres, there was another carried by a seaman.  This one gave forth a metallic clinking, as if it were full of iron eggs.  With the Doctor and the other seaman carrying two rifles each, the four men made their way slowly around the rocky hillside and were soon advancing silently, single-file, up the surface of one of those perpetual snow-banks for which the islands are noted.