"I think I've got it," he whispered. "There's a smooth spot over here." Even as he spoke, a sudden flash of bright light fell over them as a slit appeared in the side of the cliff, to reveal the familiar dome-like room. Marc stole back for another look at the guards, and finding them still unconscious, returned swiftly to the door. "Is Herrigg there?" he asked, approaching Toffee. "I don't see him," Toffee answered. "I think the room's empty." They crept forward. Toffee was right; the room was deserted. Removing his jacket, Marc moved into the passage again, and by hanging the garment on a jagged rock, managed to cover the smooth surface that opened the door. "We don't want to be trapped in here," he explained, returning inside. Then he nodded to Toffee. "Keep an eye on the guards." "Okay," she agreed. "What are you going to do?" "Look for Herrigg," Marc replied, "and try to get the jump on him." He didn't have to look far, for almost instantly there was a soft, whirring sound that announced the opening of the laboratory door. Marc dashed swiftly toward it and stood to one side. Toffee crossed to the open doorway and dissolved into its shadows. She motioned frantically to Harold, still in the center of the room, but in answer, he only blinked and swayed undecidedly from side to side, obviously blinded by the bright light. The door slid open and Dr. Herrigg stepped into the room. Whatever he had expected to find, it is certain that an alcoholic plumber was not among those items, for instantly, at the sight of Harold, he stopped short, stunned. Indeed, so acute was his surprise that he didn't notice Marc, almost next to him. The gun seemed to appear magically in the doctor's hand as he advanced slowly toward the befogged Harold. Harold, for his part, gazed uncertainly at the shocked scientist and greeted him with mistaken enthusiasm. "Got a shot, Doc?" he asked hopefully. * * * * * It was at this precise moment that Marc sprang after the doctor. Leaping lightly forward, he grasped Herrigg's upper arms firmly and pulled them sharply behind the startled man. There was a quick barking sound, and a bullet whined thinly over Harold's head, then ricocheted from the solid, circular wall. As the gun clattered to the floor, Harold followed its example, and dropped to his knees, looking much like a terrified, repentant sinner at a revival. "Cripes, Doc!" he muttered feverishly. "You got it all wrong. All I want is a drink!" "Grab that gun!" Marc panted, holding the furiously struggling doctor. "Cover him!" Toffee, like an Olympic runner in the last stretch, darted swiftly from the shadows and scooped the weapon from the floor. This time she held it correctly. "Stand back!" she yelled blood thirstily, slipping into what she believed to be the spirit of the occasion. "I'll blow his ugly head off!"