"If they are not opened, the dam will burst," begged the old man. "It is weakened now, I tell you. It cannot stand the pressure of more water. Let me up, and then you can tie me again."
Ramon seemed suddenly interested.
"You say that if the sluices are not opened the dam will burst?" he asked.
"Yes, yes! Let me up, I must open them. I——"
"Silence! And if they burst what will happen?"
"Why, the whole valley from here down is a trough! The water will rush down and destroy many lives and acres of property. Let me up, for Heaven's sake, Ramon, or if you will not let me do it, open the sluices yourself. You do not know what you are doing—every moment counts."
Again the thunder roared, and a blinding flash illumined with a blue, steely radiance the strange scene in the old dam-tender's shanty. In the brief period of lighting, Jack Merrill surprised a wickedly radiant look on Ramon's face. At the same instant a few heavy drops of rain fell on the roof.
"Hark! The rain!" cried the old man; "for mercy's sake, let me out. It is my duty."
"Which you will not perform to-night," sneered the Mexican, as the storm increased; "this storm saves us the use of dynamite."
In one dreadful flash of insight, Jack Merrill realized the Mexican's terrible plan. He had intended to blow up the dam and flood the valley below. The storm had taken the work out of his hands. The heavy rain-fall would swell the dam till the weak containing wall broke. In a few short hours every ranch in the course of the bursting dam would be devastated. Yes, that was what the fruit rancher at Maguez had told them. And there was nothing he could do but lie there powerlessly. The boy's brain seemed to be on fire, but in his veins was ice.