Crash Beam

 "I may be sticking my neck out, sir, but off hand I'd say Stevens was killed." "Killed?" Rawlins blinked at the form in the chair. "But that's impossible. The door was locked. The room hasn't been disturbed and there aren't any holes in the glass. Nothing could get in here except light." Dan walked to the big windows. He examined the ledge and the joints.

He came back to the control table and tested the switches. Suddenly he leaned over Stevens' huddled body and pulled the log book from under his stiff fingers. "Look at this!" Scrawled across the pad in big jerky letters were the words "_Purple light bea_...." The pencil had torn through the sheet in a violent final contraction. Rawlins rubbed his chin. "We don't use any purple beams. It doesn't make sense." "Maybe it does," Dan said. He turned to the doctor. "Wasn't there some experiments made by a Dr. Aren Linden several years ago on the injurious effect of certain kinds of light on the nervous system?" The doctor frowned.

 "Yes, I think there was, but the experiments were never completed." "That's right. The foundation refused to up his salary, so he went to work for Roehm." Dan swung around to Rawlins. "It was Linden who helped work out the invisible light landing system that Roehm uses on his Venus rocket ports." "Seems to me you're jumping to some pretty wild conclusions, Kearns," Rawlins said slowly. Dan looked at him. "Suppose Linden has found the exact wave-length of the most potent ray.

It would be simple for anyone to climb the framework of one of the buildings and shine that light in here." Rawlins straightened up. "I'll search every tower on the field." "But you haven't time. That passenger rocket will be here in five minutes." The supervisor sucked in his breath. "What's your idea?" "I'll sit at the control table myself. You can do the preliminary locating in the observation tower." He ran to the door. "Where's the welder that cut the lock?"

The doctor and a medic were carrying out Stevens when he came back a few seconds later. Dan was slipping on the welder's helmet. "Keep everyone away from the control-room level," he said to Rawlins. "And you better have the crash trucks and the flame quenchers standing by on the field." Rawlins stared at him. "And what happens to you?" Dan licked his lips.

 "I--I don't know. I'm going to try something." Rawlins smiled. He reached out his hand. "Good luck, Dan," he said. He clapped him on the shoulder. When they were gone, Dan dropped the helmet over his face. He walked slowly across the room with his hands in front of him like a blind man. Finally he lifted up across the room with his hands in front of the helmet and knocked out the dark glass in the eye slot. Then he slipped it back on.

Crash Beam

 The speaker at his side clicked on. He heard Rawlins' voice. "I picked 'em up, Dan. They're coming in at minimum speed--seventy point two nine five degrees. I didn't mention the freighter."

Dan flicked a small switch on the table edge. A straight white line of light shot out across the graph, then swung slowly back and forth through an arc of ten degrees like a searching feeler. Suddenly it steadied and an orange bead appeared at its terminus. Dan watched the bead travel down the line, across the pulsing capillaries. He reached out and grasped a small lever sticking out of the tabletop. As he pressed the lever to one side, the line moved around the graph like a pointer, carrying the orange bead with it. He watched it till the bead reached the center of the graph, and then glanced up through the window. Above the far end of the field, he could discern the dim orange glow of a rocket's keel jets. Suddenly he jerked back his head.

 A beam of purple light was playing back and forth across the table. It swept over his gloved hands, across his arms and chest, and moved upward toward his face. He jumped up, keeping hold of the lever, and studied the angle of the small beam. The reflection on the dark cloth of his jacket was making him dizzy. He reached into his pocket...

[Illustration: _Suddenly ... a beam of purple light!_]

From the observation tower, Rawlins watched the rocket sweep toward the field with keel jets blazing. As it reached the strip it seemed to falter and dip. Rawlins clenched his hands and swore. Then it steadied and slid into a perfect landing. The intercommunication tel audio flashed on. He saw Dan Kearns' haggard face under the uplifted welder's helmet. "Rawlins. The roof on tower three. Check it right away.

I think...." Kearns' body abruptly went rigid; he fell across the control-room table.

Dan Kearns came to on the floor of the control room with the doctor working over him.

 "How do you feel?" the doctor asked.

"Like I've been sitting in an electric chair." "You'll be all right," the doctor said.

"Compared to Stevens you got a mild dose." Dan looked around him. He saw Rawlins' boots and glanced upward. "Did you check the tower?" 

"Yep, we found him--dead. Just like Stevens. He was one of Roehm's men all right. He had a flashlight.

We tried it on one of the doc's white rats." Rawlins shook his head. "Stevens must have gone through hell." Suddenly he stared down at Dan. "But how...?" Dan smiled. He lifted up his gloved hand. In it was a small rectangular signaling mirror. "I reflected it right back at him.