From then on it was war between them. Spitz, as lead–dog and acknowledged master of the team, felt his supremacy threatened by this strange Southland dog. And strange Buck was to him, for of the many Southland dogs he had known, not one had shown up worthily in camp and on trail. They were all too soft, dying under the toil, the frost, and starvation. Buck was the exception. He alone endured and prospered, matching the husky in strength, savagery, and cunning. Then he was a masterful dog, and what made him dangerous was the fact that the club of the man in the red sweater had knocked all blind pluck and rashness out of his desire for mastery. He was preeminently cunning, and could bide his time with a patience that was nothing less than primitive.

It was inevitable that the clash for leadership should come. Buck wanted it. He wanted it because it was his nature, because he had been gripped tight by that nameless, incomprehensible pride of the trail and trace–that pride which holds dogs in the toil to the last gasp, which lures them to die joyfully in the harness, and breaks their hearts if they are cut out of the harness. This was the pride of Dave as wheel–dog, of Sol–leks as he pulled with all his strength; the pride that laid hold of them at break of camp, transforming them from sour and sullen brutes into straining, eager, ambitious creatures; the pride that spurred them on all day and dropped them at pitch of camp at night, letting them fall back into gloomy unrest and uncontent. This was the pride that bore up Spitz and made him thrash the sled–dogs who blundered and shirked in the traces or hid away at harness–up time in the morning. Likewise it was this pride that made him fear Buck as a possible lead–dog. And this was Buck's pride, too.

He openly threatened the other's leadership. He came between him and the shirks he should have punished. And he did it deliberately. One night there was a heavy snowfall, and in the morning Pike, the malingerer, did not appear. He was securely hidden in his nest under a foot of snow. Francois called him and sought him in vain. Spitz was wild with wrath. He raged through the camp, smelling and digging in every likely place, snarling so frightfully that Pike heard and shivered in his hiding–place.

"They told us up above that the bottom was dropping out of the trail and that the best thing for us to do was to lay over," Hal said in response to Thornton's warning to take no more chances on the rotten ice. "They told us we couldn't make White River, and here we are." This last with a sneering ring of triumph in it.

"And they told you true," John Thornton answered. "The bottom's likely to drop out at any moment. Only fools, with the blind luck of fools, could have made it. I tell you straight, I wouldn't risk my carcass on that ice for all the gold in Alaska."

"That's because you're not a fool, I suppose," said Hal. "All the same, we'll go on to Dawson." He uncoiled his whip. "Get up there, Buck! Hi! Get up there! Mush on!"

Thornton went on whittling. It was idle, he knew, to get between a fool and his folly; while two or three fools more or less would not alter the scheme of things.

But the team did not get up at the command. It had long since passed into the stage where blows were required to rouse it. The whip flashed out, here and there, on its merciless errands. John Thornton compressed his lips. Sol–leks was the first to crawl to his feet. Teek followed. Joe came next, yelping with pain. Pike made painful efforts. Twice he fell over, when half up, and on the third attempt managed to rise. Buck made no effort. He lay quietly where he had fallen. The lash bit into him again and again, but he neither whined nor struggled. Several times Thornton started, as though to speak, but changed his mind. A moisture came into his eyes, and, as the whipping continued, he arose and walked irresolutely up and down.

For Thornton, however, his love seemed to grow and grow. He, alone among men, could put a pack upon Buck's back in the summer travelling. Nothing was too great for Buck to do, when Thornton commanded. One day (they had grub–staked themselves from the proceeds of the raft and left Dawson for the head–waters of the Tanana) the men and dogs were sitting on the crest of a cliff which fell away, straight down, to naked bed–rock three hundred feet below. John Thornton was sitting near the edge, Buck at his shoulder. A thoughtless whim seized Thornton, and he drew the attention of Hans and Pete to the experiment he had in mind. "Jump, Buck!" he commanded, sweeping his arm out and over the chasm. The next instant he was grappling with Buck on the extreme edge, while Hans and Pete were dragging them back into safety.

"It's uncanny," Pete said, after it was over and they had caught their speech.

Thornton shook his head. "No, it is splendid, and it is terrible, too. Do you know, it sometimes makes me afraid."

"I'm not hankering to be the man that lays hands on you while he's around," Pete announced conclusively, nodding his head toward Buck.

"Py Jingo!" was Hans's contribution. "Not mineself either."

It was at Circle City, ere the year was out, that Pete's apprehensions were realized. "Black" Burton, a man evil–tempered and malicious, had been picking a quarrel with a tenderfoot at the bar, when Thornton stepped good–naturedly between. Buck, as was his custom, was lying in a corner, head on paws, watching his master's every action. Burton struck out, without warning, straight from the shoulder. Thornton was sent spinning, and saved himself from falling only by clutching the rail of the bar.

At last, at the end of the fourth day, he pulled the great moose down. For a day and a night he remained by the kill, eating and sleeping, turn and turn about. Then, rested, refreshed and strong, he turned his face toward camp and John Thornton. He broke into the long easy lope, and went on, hour after hour, never at loss for the tangled way, heading straight home through strange country with a certitude of direction that put man and his magnetic needle to shame.

As he held on he became more and more conscious of the new stir in the land. There was life abroad in it different from the life which had been there throughout the summer. No longer was this fact borne in upon him in some subtle, mysterious way. The birds talked of it, the squirrels chattered about it, the very breeze whispered of it. Several times he stopped and drew in the fresh morning air in great sniffs, reading a message which made him leap on with greater speed. He was oppressed with a sense of calamity happening, if it were not calamity already happened; and as he crossed the last watershed and dropped down into the valley toward camp, he proceeded with greater caution.

Three miles away he came upon a fresh trail that sent his neck hair rippling and bristling, It led straight toward camp and John Thornton. Buck hurried on, swiftly and stealthily, every nerve straining and tense, alert to the multitudinous details which told a story–all but the end. His nose gave him a varying description of the passage of the life on the heels of which he was travelling. He remarked the pregnant silence of the forest. The bird life had flitted. The squirrels were in hiding. One only he saw,–a sleek gray fellow, flattened against a gray dead limb so that he seemed a part of it, a woody excrescence upon the wood itself.

"Old longings nomadic leap,
Chafing at custom's chain;
Again from its brumal sleep
Wakens the ferine strain."

Buck did not read the newspapers, or he would have known that trouble was brewing, not alone for himself, but for every tide–water dog, strong of muscle and with warm, long hair, from Puget Sound to San Diego. Because men, groping in the Arctic darkness, had found a yellow metal, and because steamship and transportation companies were booming the find, thousands of men were rushing into the Northland. These men wanted dogs, and the dogs they wanted were heavy dogs, with strong muscles by which to toil, and furry coats to protect them from the frost.