“That’s a good plan, lad,” the Marshal said with an approving glance at him. “We will arrange to arrive at their mountain retreat at five o’clock tomorrow morning. It won’t do to make the attack at night, for if anything went wrong they could kill the prisoners before we knew it. I’ll send Jean Barry to the Ricker ranch with my automobile, and have Big Joe get all the men together. Our party will join them there in time to reach the counterfeiter’s stronghold by five o’clock to-morrow morning.” “Jack, have the cowboys take their horses along with them to the ranch, and I will take you there in my airplane,” Roy cut in. Mason looked at his watch. “That will be fine,” he said. “It is just one P.M. and I won’t have to start from here until about five o’clock if I go by airplane. We are all to meet at the Ricker ranch and make a start from there some time during the night. The Marshal and Bud have the trip timed so we will reach the counterfeiter’s stronghold early in the morning and take them by surprise.” Mason and Roy laid a plan for the latter to be in the vicinity of the mountain retreat, and after Mason had set off the explosive charge and a successful rescue was accomplished, Roy was to carry the glad news by airplane to the girls’ anxious parents. They put in some of the time going over the airplane and getting it in order. The Marshal and Bud had left with the last cowboys, and at five o’clock Mason and Roy started their flight. In a short time they had overtaken and passed the Marshal’s riders. Arriving at the Ricker ranch they made a safe landing and immediately turned in to get a little rest. Mason’s sleep was fitful, and he was glad when aroused by the Marshal and told that the hour had struck. The dynamite with wire and a battery was given to him, and Scotty was carefully rehearsed in the part he was to play. The moon was shining as the grim riders formed and set out rapidly for the foothills. Sunrise found them concealed at the base of the outlaws’ stronghold. Mason and Scotty began their perilous climb to the semicircle of rock. It was thought to be utterly impossible to approach closer than a hundred yards to the stronghold without being challenged by the guards. It was the brave Scot’s duty to open fire the minute he was challenged and attract the outlaws’ attention while Mason was to crawl to a position where he could place the charge of dynamite to the best advantage. When the charge was planted he was to set it off, while the Marshal was to hurl his men on the outlaws before they could recover from their surprise.