Rick had no answer. "Let's go over to the shore. Joe's men ought to be at the rowboat by now. Maybe they found the girls." Scotty banked around and headed over the clump of birches. In a small clearing behind the clump they saw two men in Scout uniforms. The men looked up, and one spread his hands wide in a gesture that said nothing of importance had been turned up. "There's only one thing to do," Rick said decisively. "We've got to check on the..." He stopped as though a hand had clutched his throat. Barby's voice, in his earphones! Rick pulled the unit from his pocket and turned up the volume. He couldn't hear her well. "It's Barby," he said swiftly. "Circle!" Rick strained to hear. She was talking to someone. "... It won't do the slightest bit of good to keep us here, because my brother will know where we are." The signal faded as she talked. Rick turned the little radio unit, trying to keep the volume constant. "You'd better let us go," Barby was saying. "You'll get into a lot of trouble if you don't." Rick groaned. Her threats would do about as much good as a bunny threatening a wolf pack. Where was she? On the houseboat? Suddenly he realized ... he had the key in his hands! Barby's voice was high-pitched and frightened now. "What are you doing? Why are you putting that plastic cap on Jan?" Rick turned the radio unit as the plane circled. The sweat stood out on his face. Unerringly, the axis of the built-in antenna pointed to the houseboat. There was no longer any doubt! "Land!" he yelled. "Land next to the houseboat!" Scotty slammed the throttle in instant response, and as the Sky Wagon dived toward the water he cast a quick look at Rick. "What did you hear?" Rick was already slipping off his shoes, getting ready to jump. "On the houseboat!" he choked. "They're using the mind reader on the girls!" CHAPTER XVIII The One-Man Boarding Party Scotty hit the water and bounced once, but he held the plane down and in a moment the water slowed it. He revved up again and taxied as rapidly as he dared to the houseboat, swung broadside to it, and throttled back. Rick was waiting. He flung the door open and dove far enough to clear the pontoon. The cold water closed over him briefly, then with a powerful kick he flashed to the surface again. A few strokes brought him to the houseboat. The two men were leaning on the rail. One, a hefty man of middle age with a striped shirt and glasses, said politely, "Do you want something?" Rick stopped and tread water. "I want the two girls you have inside. Have them come out here, and we won't bother you any more." The second man, the dark-haired one who had come to Spindrift, smiled. "You mean our wives? They're having a nap. Sorry." "I mean my sister and her friend. Stop stalling, Mister." Striped shirt shook his head. "Sorry, boy. We haven't seen your sister. Now climb back on your little airplane and get out of here."