Rick and Scotty started work right away. The police driver sat in a chair and watched them. He spoke English, but wasn't much of a conversationalist. After a while the boys forgot he was there.

Listening to the s.p.a.ce signal was strange. As the tape ran through, Rick was certain his ear detected a kind of pattern in the sounds. There was a continuous hiss; that was normal hydrogen on the 21-centimeter wave length. Then there were sharper hisses, as though some strange creature was trying to send a coded message through the noisy hydrogen background.

"It's a message of some kind," Rick stated. "I'll bet on it."

"Who sends messages from s.p.a.ce?" Scotty asked with a grin. "Ghouls, ghosties, or long-legged beasties?"

"Don't laugh," Rick said impatiently. "Didn't you ever hear of Project Ozma?"

Scotty hadn't. "The wizard of Ozma?"

"The name comes from Princess Ozma of Oz, I guess, but it was the first project to use the Green Bank telescope to try to locate intelligent signals from s.p.a.ce. Stuff exactly like this."

"You're kidding!"

"Nope. On the level."

Scotty listened to the continuous signal, his face thoughtful. "Maybe there is intelligence behind it. And maybe not. I don't get much of a pattern out of the sounds."

"Maybe the seven-eyed men of the planet Glup don't have rhythm," Rick began. "Anyway ..."

He never finished the sentence. The control-room door slammed open.

Arabs crashed through, bringing the police guard to his feet with a bound. He s.n.a.t.c.hed a pistol from a shoulder holster and got off two shots before an answering shot caught him and spun him around with the impact. The police guard slid slowly to the floor!

CHAPTER XVIII

The Fight at Sahara Wells

The pistol dropped from the police driver's nerveless hand and Scotty leaped. Rick dropped to the floor as his pal picked up the pistol and rolled, shooting as he turned. His second shot caught an Arab and slammed him back into the others who were trying to crowd in.

Rick looked frantically for a weapon. The only thing in sight was a heavy ceramic ash tray that the guard's fall had knocked to the floor.

He grabbed it and threw, rising to one elbow. The ash tray caught an Arab in the throat. Someone shot, and chips flew from the cement floor next to Rick's head. He rolled away.

Scotty aimed with care, as coolly as though he stood on the range back home. He squeezed the trigger and was rewarded by a choked yell from beyond the doorway. He fired again, and a burnoosed figure grabbed the doorframe for support.

The Arabs beyond the doorway had dived for cover, leaving the doorframe clear except for the most recent victim of Scotty's shooting and the one Rick had hit. He was lying on the floor with both hands clutched to his throat, gagging and gasping for air.

A headdress was thrust around the frame and Scotty squeezed off a quick shot. The hammer clicked harmlessly. He was out of ammunition! He threw the pistol and the head vanished.

Both boys got to their feet and crouched to rush any newcomers. They whirled at the tinkle of broken gla.s.s behind them.

Youssef stood in the window, a Sten gun trained on them. Rick looked at the deadly little submachine gun and gulped. He remembered what Ben had said about removing the evidence.

The thief said, "Put both hands on top of your heads."

The boys did so, with no hesitation. In spite of Youssef's apparently casual manner, both knew he would not hesitate to shoot. He raised his voice and shouted in Arabic. The boys stiffened as footsteps sounded behind them and gun muzzles were thrust into their backs. Youssef vanished from the window and reappeared in a moment through the door.

"You're a difficult young man," he told Rick. "But the time for being difficult is over. I want the cat, now."

"I left it in Ha.s.san's car," Rick said, with pretended hopelessness.

Youssef spoke in Arabic. The pressure of the gun muzzle left Rick's back. He felt a cord being slipped around his forehead, a cord with hard knots that fell across his temples.

"What you feel is a strangler's cord," the thief said grimly. "Don't be a fool. The cat means nothing to you; you were merely a messenger boy.

Give me the cat and you will be left alone."

"Not until the evidence is destroyed," Rick thought. "Not until we're dead."

"It's in the car," he repeated.

Youssef lost his composure. He snapped an order in Arabic and the cord tightened. Rick gritted his teeth. Next to him, Scotty bent forward.

"Don't try it," the thief grated. "I only need one of you." His black eyes bored into Rick's. "One of my men watched you and Moustafa search Ha.s.san's car this morning. The cat was not there. Where is it?"

Rick started to shout that he didn't know, when a burst of shooting accompanied by wild yells broke out outside. Youssef spoke quickly in Arabic, then turned to the boys. "Sit down in those chairs. Move, and you die. I will deal with you when I have found out what this is all about."

The shooting gained in volume and the yells increased. The boys took the seats and stared at the big Sudanese, who was covering them with the Sten gun. The strangler's cord was draped carelessly about his neck.

"That's a real gun fight outside," Scotty whispered.

Rick nodded. He could detect several guns of different calibers, and the chatter of Sten guns was distinctive. What was going on?

The shooting lessened, then stopped altogether. The shouting increased.

The big Sudanese kept glancing over his shoulder at the doorway, as though fearful of what he might see, but he always glanced back too quickly for the boys to act.

"Watch it," Scotty said from the corner of his mouth. Rick casually got his feet under him and tensed.

Scotty's eyes opened wide and he choked, "Inspector!"

The Sudanese whirled, Sten gun ready, and the boys left their chairs in a bound. Rick dove for the thief's knees while Scotty smashed straight into him like a battering ram. The big man toppled over backward, his blazing Sten gun chipping plaster from the ceiling.

Rick let go of his grip on the knees and clawed for the man's throat.

Scotty concentrated on the Sten gun, grabbing the hot barrel and bending backward.

The big Sudanese heaved, and Rick felt as though he was a terrier hanging to a wild bull. The man was incredibly strong. The boy grabbed his throat in one hand and fended off crushing blows with the other.

He was concentrating so hard on holding his grip that a newcomer who ran into the control room had to yell. "Get up, I said. All of you!" A heavy foot crashed down on the Sten gun and held it.

Rick looked up, dazed with effort, into the cold face of Kemel Moustafa.

Third Brother had a Luger automatic, and he looked ready to use it.

The boys rolled away and got to their feet. The Sudanese got to his knees and started to get up. Moustafa struck with the Luger and the man collapsed.

The pistol muzzle pointed at Rick. "You double-crossed me," Moustafa grated. "You were supposed to give me the cat an hour ago at the hotel.