"Here, you little runt," Grim's voice boomed at him, "stop jumping around, and tie up this Mercutian. We have no time to waste." Wat groaned comically. "See how that big ox orders me around," he proclaimed, but he picked up the wire and in a trice had the guard helpless and glaring. Hilary had recovered his speech. "Thanks, boys," he told them simply. "I knew you'd come if it was humanly possible. But how did you manage to get through the Mercutians? The building is honeycombed with them." * * * * * Morgan grinned. "We came in the _Vagabond_," he said. "What," almost yelled Hilary, "you mean--" "That your ship is resting comfortably outside on the terrace. When little Wat here caught your message in the communication disk, we were busy organizing companies of Earthmen in the hills back of Suffern. As recruits poured in, we'd tell them off in hundreds, appoint officers, see that they had arms, or gave them directions where to find the old caches, and hustled them off. Had to shift our quarters continually, because Mercutian fliers would pick us up with their search-beams, and start raying. Had some close shaves. But when we heard you were caught, we turned over the command to the nearest new officer, hurried to the gorge, and here we are. The _Vagabond_ handled beautifully." "I could take her myself to the Moon," Wat boasted. "Hadn't we better be going?" Joan asked anxiously. "There is work first to be done," Hilary, answered grimly. "There's a certain weather machine in the laboratory I want to take a look at." "Weather machine?" Grim echoed, puzzled. "Yes. The Viceroy let something slip about it. For some reason it's very important to them that it continues to function. I'm curious." A gasp from Joan. Surprised, the men turned to her. "Of course," she said breathlessly. "Father had been working on it for the longest time. It was a machine to control weather. Something to do with broadcasting tremendously high voltages, ionizing the air and causing rain clouds to form or reversing the process and scattering clouds back into thin air. This was the Master Machine. All over the Earth, at spaced distances, were smaller replicas, substations, controlled from this one. He had great hopes of furnishing equable weather to all the Earth. It was just completed, when...." She trailed off. * * * * * Grim frowned. "Very interesting, but what is so terribly important about it now?" "You fool," Hilary exploded, "it's as important as hell. Don't you see? What are the Mercutians' weapons? Sun-tubes, sun-rays from their fliers, tremendous burning disks that are their space-ships. Sun--sun--everything they have depends upon the sun. Take away the sun, and what have they? Nothing but their hideous giant bodies--they are weaponless. Now do you see?" He fairly shouted at him. Grim's face lit up heavily; Wat was dancing insanely.