"Misfire!" he cried. He drew back the bolt and inserted a fresh cartridge. Again the gun clicked harmlessly. Dr. Bird ejected the shell and examined it. A deep indentation appeared on the primer. Hurriedly he tried a half dozen more cartridges but they refused to explode. He turned a keen gaze toward the trucks. On the ground was set a tube-like projector pointing toward them. Dr. Bird swore softly and jerked his pistol from its holster. The hammer clicked futilely on a cartridge. "Stymied!" he exclaimed. "They have that portable ray mechanism, with them, which disabled our bombs. It's hand to hand, Carnesy, old dear. I wonder where McCready is." * * * * * The Russians approached slowly, keeping their lines straight. They were within two hundred yards of the knoll. Suddenly from a point a hundred yards to the left of the end of the land came a rattle of fire. The attacking line dropped in a pile of grotesque heaps. "It's McCready!" shouted Carnes. A little ravine ran from the knoll toward the trucks. Sitting in the ravine was the lieutenant, playing a Browning machine gun on the line of attackers. When there were no more of them on their feet, he turned his gun on the trucks. Panic seized the Russians and they made a rush for their truck. Their leader leaped among them, yelling furiously. They paused and turned to the projector tube. Slowly they swung it around. The lieutenant's gun ceased firing. As the Russians rushed the now silent gun, Dr. Bird stepped to the gun on the knoll. He trained it and pressed the trigger. A rattle of fire came from it and two of the rushing figures fell. The attack paused for an instant. McCready had risen to his feet and was running up the ravine with his gun under his arm. "Good head!" cried Dr. Bird, "Clever work! Watch the fun now." He ceased firing his gun. The Russians wavered and then rushed the point from which McCready had fired. The lieutenant allowed them to get to within a short distance and then crumpled the attack with another burst of fire from the flank. With cries of alarm, the Russians turned and fled toward their trucks. McCready ran along the ravine until he was within fifty yards of the standing machines. As the Russians approached, one of them stepped to the truck crank. McCready's pistol spoke and he dropped. A second shared his fate. With cries of despair, the Russians climbed into the remaining truck whose motor was running. Rapidly it drove away across the plain. McCready rose from the ravine and ran toward the standing truck. He started the motor and headed for the knoll. "He's got a truck," cried Carnes. "We can get away in it." "Where to?" demanded Dr. Bird. "Archangel is between us and the _Denver_." The truck came up. "Come on, Doctor," cried McCready. "Hurry up. We'll take the battery out of this truck and get our plane going."