Forward they dashed once more, not neglecting, however, to keep wary watch as they ran. No more of the enemy were seen, however. There was a sudden uproar ahead, the shots ceased. Cries of astonishment, stupefaction, even a note of fear, went up from several throats. Above all was a bull-like roar that they readily identified as coming from Bob's throat.

Frank's heart gave an exultant leap. He knew that yell. It came only when Bob went berserk, and fought with his hands. He had heard it when they fought Mexican bandits, Chinese smugglers, rum runners on Long Island and Incas in the Andes. He knew well what it meant.

Almost at the same moment, they burst into the glade at the base of the knoll, and came to a dead halt, eyes popping, standing as if rooted to the spot.

But only for a moment. Then they started tearing up the hillside, among the scattered trees. For at the top was a whirling heap of figures, as if caught up in a cyclone, and well they knew what it portended.

Somewhere in the center of the group was big Bob, at close grips with the enemy, and not caring how many they numbered.

Would they be in time? Could they help Bob before some half-breed succeeded in sticking a knife into him?

But Bob proved that he could handle his own affairs, for while they were still several yards away, first one and then another half-breed was spewed from the miniature whirlwind, and then Bob could be seen with several men clinging to his legs and another on his back, attempting apparently to throttle him. The big fellow's hands went up and back.

They settled under the other's armpits. There was a sudden mighty heave and wrench, and then the man on Bob's back came flying through the air, straight for Bob's two comrades. He had been tossed from Bob's shoulders, as a strong man would toss a sack of meal. Frank and Jack leaped aside, and the man struck the ground, rolled over and over and then lay still, crumpled up against the trunk of a spruce.

Recovering from their surprise, Jack and Frank leaped forward. But their intervention was unnecessary. Standing like a young Colossus, legs apart, with a man wreathed about each, Bob bent down. One big hand seized each by the neck. Then the two heads were b.u.mped together once, twice. The half-breeds collapsed. Their grip on Bob's legs relaxed, and he tossed them aside, and they, too, lay still. He had knocked them out.

Then Bob did a surprising thing. He leaped with a murderous look for the two boys.

"More of you, hey?"

They sprang aside nimbly, eluding his grasp.

"Bob, Bob, it's us."

"What? What? Oh, you-"

Bob looked at them, the battle l.u.s.t dying in his eyes, and recognition dawning. It was followed by a wide grin.

"Oh, it's you."

"Bob, old thing, that was the greatest fight in history," cried Frank, hysterically, clapping his chum on the back.

"Never saw the like," said Jack, doing likewise. "Thank G.o.d, Bob, you're alive."

"Never was more alive in my life," said Bob. "Hey, they're running away."

He darted away from his chums and sprang downhill. True enough. The two whom he had disposed of first, who had dropped out of the fight, had gained their feet and were running madly through the trees.

Jack ran after Bob and restrained him.

"Let them go, Bob. They are alone. There are three others here we must tie up before they come to."

Bob followed him back to where Frank was bending over the man whom the big fellow had tossed over his head. The half-breed was recovering consciousness, and beginning to moan.

"Broken arm, I think," said Frank. "He'll not bother us. How about the two whose heads you b.u.mped together?"

"They're recovering consciousness, too," said Jack. "Nothing much the matter with them. We had better tie them up, so they can't cause us any trouble."

"Here, take the other fellow's belt and tie his hands behind his back with it," said Bob. At the same time, he suited action to word in the case of the nearer of the two, whipped off the fellow's belt and tied him with it.

"Won't they try to run away, Bob? Ought we to tie their legs, too?"

"No, we'll just keep an eye on them. Let's take a look at the other. If his arm is broken we'll have to set it somehow, I guess. Rather pitch him in the lake, though. He's a villainous looking rascal. Tried to choke me, too, and darn near succeeded."

While Frank kept an eye on the two other prisoners, who had now recovered consciousness and were beginning to realize their situation but lay still under the threat of Frank's rifle, Bob and Jack examined the third man.

His senses were returning, and he moaned a good deal. Examinations revealed, however, that his arm had not been broken, merely badly wrenched.

"I'm mighty glad of that," said Jack. "We'd have been up against it to set a broken arm."

"Oh, we could do it, all right, if necessary," said Bob. "But I'm glad, too, that it isn't necessary. But, say, Jack"-with sudden recollection, and an air of anxiety-"there were four more of these scoundrels. We'll have to look out for them."

Jack's voice shook a little as he replied.

"I think not, Bob," he said. "Frank and I saw them first. We ambushed them, practically. They didn't have a chance."

"You don't mean-"

Jack's gaze was steady but troubled.

"We had to do it, old man," he said. "It was our life or theirs. And yours, especially. When we heard your shout, and those first shots, Frank went wild with fear that you had been trapped while we were away enjoying ourselves. And I guess I felt as bad as he did."

"Hey, fellows," interrupted Frank, hailing them, "the two that got away must have been all that were left. They've jumped in a canoe and are paddling like mad for the mainland."

"Can you see them?" called Jack, starting to the top of the knoll to join his chum.

"How would I know what they were doing if I couldn't?" rejoined Frank.

"Yes, I can see them. Look there."

He pointed.

"Tie up that other fellow, Bob, and make him walk up here to join his little playmates," Jack called back.

Bob complied. The man groaned, but by now he had fully recovered his senses, and he obeyed Bob's order to move with an alacrity that showed he stood in abject fear of the husky young American.

Frank pointed out the fleeing men, who were nearing the mainland, and paddling with superhuman energy, as if fleeing from the Old Nick, no less.

"That accounts for all of them, I guess," he said. "So we can sit down now, Bob, while you tell us how it happened."

"Not much to tell," said Bob, sinking to a seated position against the tree trunk. "Except I went to sleep and was almost surprised, but not quite. My first intimation that the enemy was near was when I heard somebody talking in the trees at the foot of this knoll. Or, did I hear anybody? Was it just the old sixth sense giving warning of danger? I don't rightly know. At any rate, I woke with a start and looking down through the trees saw a bunch of half-breeds making their way towards the other side of the island.

"I tell you I was scared. I felt guilty as sin. Here I had promised to keep watch, and, instead, had fallen asleep. As a result, the half-breeds had landed on the island, and were heading for where you fellows were swimming. I had endangered your lives. What should I do?

That was the question.

"But I didn't waste must time, puzzling over it. I knew I had to give you fellows warning or you would be taken by surprise. So I yelled to you as loud as I could to look out. I guess they hadn't seen me up till then. But when I yelled, they saw me quick enough, and several of them opened fire, and--"

"Wait a minute, Bob," Frank interrupted, his eyes shining. "They hadn't seen you, and you could have let them pa.s.s without attracting their attention, but you yelled, just to give us a chance for our white alley.

That's, that's-"

"Oh, forget it," said Bob, uncomfortably. "You'd have done the same.