"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.