"Shut up!" hissed young McCrae fiercely. "_Keep_ him quiet, Tom!"

"Shut up, Oscar!" growled McHale. "Don't you savvy nothing? You and me ain't in on this. Stand right still now, and don't breathe no harder than you have to. Go to it, boys!"

If young McCrae had been a prowling animal before, he was now the ghost of one. Casey Dunne, behind him, endeavoured to copy his noiseless method of progress. Gradually they drew near the light.

They could discern the figure of the watchman beside it. He was sitting on a stick of timber, smoking. McCrae drew from his pocket a long canvas bag, of about the dimensions of a small bologna sausage, and weighed it in his hand. They crept nearer and nearer. They were not more than ten feet away. The guardian of the dam laid his pipe on the timber, rose to his feet, and stretched his arms high above his head in a huge, satisfying yawn.

At that instant McCrae sprang like a lynx on a fawn. The sandbag whistled as it cut down between the upstretched arms, and the watchman dropped as if hit by lightning.

"That was an awful crack, Sandy," said Casey reprovingly. He flashed the lantern at the face, and slipped his fingers to the wrist. To his relief, the pulse was strong.

"I had to get through his hat, hadn't I?" said McCrae. "I wasn't taking any chances. He's got a head like a bull. Come on, let's fix him up."

The watchman came out of their hands trussed up like a fowl for roasting, securely gagged, with a gunny sack drawn over his head and tied at the waist. They lifted him between them and bore him away from the dam to what they considered a safe distance.

"'Watchman, tell us of the night,'" chuckled Casey. "He's all right, by the way he kicks, and nothing can hit him away out there. They'll see him first thing in the morning. Hustle up Oscar, now. This is where he gets action."

Oscar, when he came up, got to work at once. Because the planting of shots by different men would have been both unsatisfactory and dangerous he worked alone. The others lay flat in the gloom, watching the lantern which he had appropriated flitting here and there along the structure.

"Oscar's some powder man, you bet," McHale observed. "He don't look like he had the savvy, but he'll cut them fuses so's the shots'll come mighty near together. Blamed if I know why a Swede takes to powder.

Seems to come natural to 'em, like pawin' snow to a cayuse."

The light blinked and disappeared as Oscar descended. Followed a long interval of silent waiting. Then across in the camp a dog began to bark, at first uncertainly, with what was almost a note of interrogation, and then, as the wind brought confirmation of suspicion to his nostrils, with savage vigour. By the sound, he was apparently approaching the dam.

Some sleeper, awakened by the noise, yelled a profane command to the animal, which had no effect. It merely awakened another, who cursed the first sleepily.

"Hey, Kelly," he called, "hit that dog with a rock!" A pause. "Hey, Kelly, wake up, there!"

"I guess we've got Kelly," Casey whispered to Sandy. He called out hoa.r.s.ely: "He'll quit in a minute! G'wan to sleep. You don't know your own luck."

But the dog continued to bark, jumping up and down frantically. A light appeared in a window of one of the shacks.

"Blazes!" muttered McHale, "somebody's getting up."

A low whistle came from behind them. It was significant of the tension of the moment that both McHale and McCrae jumped. But Dunne was cooler.

"That's only Wyndham with the horses," he said.

Suddenly a long aperture of light appeared in the dark wall of the shack. For a moment it was partially obscured by a figure, and then it vanished utterly. The door had closed. The light from the window remained.

"Somebody's come out," said McHale. "That's about where Farwell's shack is. What's keepin' Oscar? He's had time enough. Maybe I'd better go across and hold up this feller? We don't want----"

The lantern bobbed into view once more. Oscar was coming at last, but he was taking his time about it. Had he placed the powder? Had he fired the fuses? Or had something gone wrong at the last moment? They asked themselves these questions impatiently. It would be just like him to have forgotten his matches. It might not occur to him to use the lantern flame. In that case----

"Come on, hurry up there!" McCrae called softly.

Oscar clambered up beside them. "Ay tal you somet'ing----" he began.

But the dog yelped suddenly. A sharp voice cut across to them:

"Kelly! What the devil's going on here? What are you about? Who's that with you?"

"Farwell!" Dunne whispered. "Did you light the fuses, Oscar?"

"Sure t'ing," Oscar replied. Proud of the phrase, he repeated it. "She ban light, all right."

"When'll she fire? Quick, now?"

"Mebbe fema minute. We ban haf lots of time to gat out of har. Say, Kessy, what faller----"

An oath cracked in the darkness like a rifle shot.

"You, Kelly, answer me! Come across here at once!" He paused for a moment. "By thunder! Kelly, I'll come over there and----"

Casey Dunne did not hear the conclusion of the sentence. His mind was working swiftly. For, if Farwell tried to come across, he would probably be killed by the coming explosions; and that must be prevented at any cost. The destruction of the dam was justifiable, even necessary. But homicide with it would never do. To shoot in self-defence or to protect his rights was one thing; to allow a man to be killed by a blast was quite another. But just how to prevent it was the question.

"Come along, Casey," McHale urged. "We ain't got too much time."

"Time or not, we can't have Farwell hurt. You go. I'll be after you in a minute."

"If you stay we all stay," said McHale. "Let him take his chance. Come on!"

"Git, I tell you," Casey insisted. "I've got to keep him where he is till the first shot goes." He called out: "All right, Mr. Farwell. You don't need to come. I'll be there."

"That's not Kelly's voice," snapped Farwell. "What deviltry's going on here?"

By his voice, Casey guessed that he was advancing. He dropped the pretence as useless. "Get back, there!" he ordered sharply, but endeavouring to disguise his natural voice. "Get back to your shack, you, or I'll drill you!"

Farwell's response came with surprising promptness in the form of a revolver bullet that sang just above Casey's head. By the momentary flash of the weapon his big figure was just discernible standing bent forward, legs wide apart, tense and watchful.

As Casey's hand dropped to his automatic, McHale clutched his wrist.

"Don't shoot!" he whispered.

"I'm not going to hit him," Casey replied. "I'm just going to make him stay where he is."

"Let me," said McHale, and fired as he spoke. Farwell's revolver answered. They emptied the guns in the darkness; but as one shot high by accident and the other low by design, no damage ensued.

The camp, aroused by the shooting, buzzed like a hornet's nest. Lights appeared everywhere. Dark figures streamed out of doorways and thrown tent flaps; and, once outside, stood in helpless uncertainty.

"Coom, coom!" cried Oscar. "Ve gat out of har!" They rose and ran in the dark.

A mighty roar drowned the echoes of the pistol shots, as the ba.s.s bellow of his sire might dominate the feeble bleatings of a new-born calf. A vivid flash split the night. In the momentary illumination details were limned sharply--the buildings, the groups of men on one side, the running figures on the other. And poised, stationary, as it seemed, in mid-air, above the instant eruption, hung a mushroom cloud of smoke and dust, specked with fragments of riven wood and shattered concrete. Through the succeeding contrasted blackness the debris thudded upon the earth. With scarcely an interval followed a second shot, a third, a fourth. The air became alive with hurtling ma.s.ses raining from the heavens.

The four dynamiters reached Wyndham, who, cursing in his excitement, was straining every muscle and a comprehensive vocabulary in an effort to hold the frightened horses.

Casey, McHale, and Sandy seized their nigh stirrups, shot them at their left toes, gripped saddle horns, and went up in an instant. Oscar, less expert, fumbled for a hold with his toe, hopping on his right leg as his horse sidled and backed.

"Stand still, Ay tal you!" he gritted. "By Yudas, Ay club hal from you purty kvick!"