many days of travel they had made their way far into the interior of Alaska, well away toward the Yukon. Day by day they had broken trail for their dogs and day by day moved forward. At first the trail had been hard-packed from many dog teams passing from village to village. But as they pushed farther and farther into the wilderness these villages had vanished. Towns that were towns only in name greeted them now as they advanced. An Indian’s hovel here, the shack of a long-bearded patriarch of a miner there, that was all.

Snow had fallen in abundance. They were obliged to break every foot of trail before their dog teams.

Food was scarce. The question of feeding their dogs had become a problem. Then, only this very afternoon an Indian had told of a cache of caribou meat some ten miles away in the forest. If they would wait for him to bring it, they would have fine fresh meat in abundance.

The boys had debated the question. They were eager to go forward. A whispered message of the night before had led them to believe that their quest was nearing its end; that the man they sought was not far before them on the trail; yet the dogs must be fed.

It had been decided at last that Joe Marion with an all but empty sled should await the supply of meat, while the others pressed on breaking the trail until near nightfall, when they would make camp and await his arrival.

Curlie and Jennings had carried out their part of the program, but when he should have arrived Joe had not appeared, rounding the clump of spruce trees to the south of them.

After an hour of anxious waiting, Jennings, taking his rifle, had gone out to search for him.

“May have lost his way,” he had commented.

Curlie had remained to listen in on his radiophone. Joe carried with him, attached to his sled, a complete sending and receiving set. In time of trouble the first thing he would think of would be getting off a radiophone message to his companions.

“Ought to be getting something,” Curlie mumbled. “I wonder what could have happened? I wonder—”

He paused for reflection. Night by night as he had sat upon his sleeping-bag, listening in, strange messages had come to him from the sky. Now the rude interference of the unknown man who had been tearing up the traffic of the air told Curlie that they were coming closer to one another, and now the whisper of the girl, that ghostlike creature who appeared to haunt the track of the lawbreaker, told Curlie of the day fast approaching when he and the outlaw of the air must meet face to face. At such times he had wondered if he should then meet the girl as well as the man.

On the previous night the whisper had informed him that they were but seventy-five miles apart.

“Coming, coming,” Curlie had whispered to himself.

The trail had been heavy. They had made but fifteen miles. What of the stranger? How far had he come?

Curlie’s heart skipped a beat at the realization that he must be very near at hand.

At the same time there came a disturbing question. Had this man of evil intentions somehow stolen a march on them? Had he been in league with the Indian who had claimed to possess a supply of caribou meat? Had this been but a ruse to get them separated?

“Well, if it was, it’s been a complete success,” he exclaimed. “Three of us and not one of us knows where the others are.”

Turning, he reached for a box-magazine rifle. After examining the clip in the chamber, he slipped three other loaded ones in his pockets.

“You can never tell,” he whispered, “you sure can not.”

A great silence hovered over the forest which bounded the banks of the Tanana River. Such silences existed in these Arctic wilds as Curlie had never before experienced.

“Fairly spooky,” he whispered to himself. “Wish I could hear something—wind in the treetops, even. But there’s not a breath.”

The forest lay all about him. Everywhere the ground was buried in two feet of snow. Muffled footsteps might at this moment be approaching the camp.

At last, unable to bear it longer, he snapped off the radiophone for a moment to adjust a smaller set and tune it to 200, the wave length he and Joe had agreed to use if in distress.

When this smaller set had been called into action, he tuned the larger set to longer wave lengths. He hoped to catch some sound from the air which might relieve the awful silence.

“Wonderful thing this radiophone,” he told himself. “Great boon to the Arctic. Think of the trader, the trapper, the gold hunter alone in his cabin, tired of the sound of his own voice and that of his dog. Think of being able to tune in on his radio and bring down snatches of song, of instrumental music and of ordinary conversation, right out of the air—some young girl sending her lover a good-night kiss, for instance,” he chuckled to himself. “But—”

He paused abruptly. He was getting something on the long wave lengths. Faint, indistinct at first came the message. Yet he caught it clearly. His nerves tingled as he listened. It was Munson, the great Arctic explorer. He was attempting to inform the outside world, especially the men who had financed his expedition, of his plans. He had established a large supply station on Flaxman Island; then he had pushed fearlessly out through the floes toward the Pole. His ship was strongly built, with an extra covering of iron-wood on its keel. Its engines were powerful. He would go as far as the steamer would carry him, then he would hop off in an airplane and attempt the Pole. He was supplied with three airplanes. In these, if his ship should be wrecked, he would be able to carry his entire company and crew to the supply house on Flaxman Island.

This brief report was followed by a personal message to his wife, then the air was once more clear. The old, monotonous silence settled down upon Curlie’s little world. During all the time he had listened in, his fingers had been flying across a sheet of paper. He had written down the message. It was within the realm of possibility that he was the only operator who had got it. In that case it would be his duty to relay it to those for whom it was intended.

During all this time one question had been revolving in his mind: Why had not the man he sought, the outlaw of the air, broken in on this message? He had been informed that this man had taken delight in breaking up Munson’s communications. Why then this silence? Could it be that he himself was out scouting around, trying to ambush Joe and Jennings and in time even Curlie himself? Or was he merely afraid of being detected at this time?

“Possibly,” said Curlie to himself, “there was something about that message which interested him. In that case he would want to hear to the end.”

Suddenly his hand made a clutch at his rifle. What was that? Had he caught the sound of a footstep or was it merely a white owl flapping his wings? He sat there listening, scarcely breathing, awaiting he hardly knew what. And, at this moment, on the 200 meter wave lengths a message came to his waiting ears.

CHAPTER V
DANGEROUS BUSINESS

The Indian who had promised to provide the boys with caribou meat had not deceived them. At the appointed hour he had returned with an abundant supply.

In his eagerness to secure provisions for a long lap of the journey, Joe had piled his sled high with meat. In doing this he had made a mistake, but this he did not know at the time.

Having paid the Indian, he lashed his rifle to the top of the load, and, shouting