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 gla.s.ses, 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."

Rick's reply was a stroke that brought him to the houseboat. He reached up for a handhold, when a boat hook suddenly touched his forehead.

"Don't try it," striped shirt said. "Stay off this barge or I'll bend this pole over your head. Now get out of here."

Rick back-pedaled helplessly. Now what? He knew there was no possibility of his climbing aboard while the men were on deck.

And what was happening inside? He swam forward, to the front of the boat, and the men followed. They could move faster than he; there was no possibility of outdistancing them.

If only he had a weapon! But wishing was useless. He had to do something! He called, "Barby! Can you hear me?"

There was no answer from inside. His pulse speeded. Were Barby and Jan all right, perhaps gagged, or had the mind reader already worked?

Rick swam away from the houseboat a few feet and floated, his mind racing. There had to be a way of getting aboard. There had to!

Where was Scotty? He listened, and heard the plane's engine on the other side of the houseboat. In a few seconds Scotty came into view.

He was on the water close to sh.o.r.e, traveling at high speed. As Rick watched, Scotty swung the plane on a line with the houseboat and opened the throttle wide.

Rick stared. Was his pal out of his mind? If he crashed the houseboat, the girls would be hurt, too! Then he realized Scotty would never pull such a stunt, no matter how desperate he became.

The men on the houseboat were at the rail now, eyes on the racing plane. In that instant Rick divined Scotty's plan, he hoped, and turned to gauge his distance. The plane was on the upper step now, almost air-borne. Even as he watched, the pontoons pulled away. But Scotty held the plane on the water, roaring propeller pointed right at the men at the rail.

Rick put his head down and sprinted for the front of the houseboat. He had to time it perfectly!

To the horrified eyes of the men at the rail a collision was inevitable. They could only a.s.sume that the madman in the plane was going to smash right into them. And as Scotty had planned, they lost all interest in Rick, in the presence of immediate, personal danger.

The men threw themselves to the deck, clawing frantically for some kind of cover. At the last instant, Scotty pulled the plane up in a power climb. So near disaster had he come that the suction of the pa.s.sing pontoons lifted a coiled rope into the air on top of the cabin. Even as he mounted the rail and stood on deck, Rick gave a prayer of thanks for his pal's perfect judgment and lightning reflexes.

[Ill.u.s.tration: "_Stay away or I'll bend this pole over your head!_"]

He ran along the deck, jumped over the two prostrate men, swung around and launched himself into the cabin. He stopped, eyes wide with fright.

Barby was lashed to a chair just inside the door, a gag in her mouth.

Jan was on the other side of the cabin, also lashed. But Jan had a plastic cap on her head, and wires ran from it to a machine on a nearby table. Two women were standing over the girl, and one had a pistol in her hand.

Rick started forward, then stopped helplessly. The pistol wasn't pointed at him. It was pointed at Jan's head!

He looked into Jan's pleading eyes and shifted his weight uncertainly.

He didn't know what to do now.

Jan did. Her arms were lashed tight, but her legs were free. She lifted one of them in a kick that caught the pistol-holding woman behind the knees. The pistol hand lifted as the woman flailed for balance, and Rick sprang like a charging fullback. His widespread arms embraced both women and slammed them back into the cabin wall. Then he scrambled to his feet in search of the gun. It was under Jan's chair.

He bent to pick it up when Barby gave a m.u.f.fled cry from behind the gag. Rick whirled.

The two men were rushing him from the cabin entrance.

There wasn't much room in the cabin, but it gave Rick an advantage. He dove toward the men, who stopped their rush briefly. But Rick hadn't made the dive with the intention of meeting them head on. There was a table along the wall next to the corner where Barby was tied up. Rick went under it.

The men rushed for the table. Rick reached out and grabbed an ankle.

Bracing his legs, he gave a mighty heave. Striped shirt went over backward in front of Barby, who stamped with both bare feet on his stomach. The breath went out of him with a whoosh.

Rick gathered his legs and shoved upward. The table heaved into the other man and threw him off balance long enough to give Rick a chance to get to his feet. Keeping the table between him and the dark man, Rick watched for an opening. Striped shirt was on his knees, shaking his head.

The dark man was tired of waiting. He launched himself across the table, arms outstretched. It was the best move he could have made, from Rick's point of view. The boy knew he could not compete with either man in strength. He had to depend on speed, and the infighting tricks he had learned from Scotty. He used one now. At the last moment he side-stepped and his hand flashed down. It was a judo chop, the hand held stiff, the blow delivered with the side opposite the thumb.

It was effective. The man dropped to the floor, shaking his head. Rick used the _savate_, the blow delivered with the heel. It landed against the side of the man's neck. He went over sideways.