"We mustn't underrate Chambers, however," he declared. "The man made one mistake. He underrated us. We can't repeat his mistake. He is dangerous all the time. He will stop at nothing. Not even murder."

"He's going easy now," said Russ. "He's hoping Craven can find something that will either equal our stuff or beat it. But Craven isn't having any luck. He's still driving himself on the radiation theory, but he doesn't seem to make much headway."

"If he got it, just what would it mean?"

"Plenty. With that he could turn all radiations in s.p.a.ce to work. The cosmics, heat, light, everything. s.p.a.ce is full of radiation."

"If it hadn't been for Wilson," Greg said, his voice a snarl, "we wouldn't have to be worrying about Chambers. Chambers wouldn't know until we were ready to let him know."

"Wilson!" e.j.a.c.u.l.a.t.ed Russ, suddenly leaning forward. "I had forgotten about Wilson. What do you say we try to find him?"

Harry Wilson sat at his table in the Martian Club and watched the exotic Martian dance, performed by near-nude girls. Smoke trailed up lazily from his drooping cigarette as he watched through squinted eyes. There was something about the dance that got under Wilson's skin.

The music rose, then fell to whispering undertones and suddenly, unexpectedly, crashed and stopped. The girls were running from the floor. A wave of smooth, polite applause rippled around the tables.

Wilson sighed and reached for his wine gla.s.s. He crushed the cigarette into a tray and sipped his wine. He glanced around the room, scanning the bobbing, painted faces of the night--the great, the near-great, the near-enough-to-touch-the-great. Brokers and businessmen, artists and writers and actors. There were others, too, queer night-life shadows that no one knew much about, or that one heard too much about ... the playboys and the ladies of family and fortune, correctly attired men, gorgeously, sleekly attired women.

And--Harry Wilson. The waiters called him Mr. Wilson. He heard people whispering about him asking who he was. His soul soaked it in and cried for more. Good food, good drinks, the pastels of the walls, the soft lights and weird, exotic music. The cold but colorful correctness of it all.

Just two months ago he had stood outside the club, a stranger in the city, a mechanic from a little out-of-the-way laboratory, a man who was paid a pittance for his skill. He had stood outside and watched his employers walk up the steps and through the magic doors. He had watched in bitterness....

But now!

The orchestra was striking up a tune. A blonde nodded at him from a near-by table. Solemnly, with the buzz of wine in his brain and its hotness in his blood, he returned the nod.

Someone was speaking to him, calling him by name. He looked around, but there was no one looking at him now. And once again, through that flow of music, through the hum of conversation, through the buzzing of his own brain, came the voice, cold and sharp as steel:

"Harry Wilson!"

It sent a shudder through him. He reached for the wine gla.s.s again, but his hand stopped half-way to the stem, paused and trembled at what he saw.

For there was a gray vagueness in front of him, a sort of shimmer of nothingness, and out of that shimmer materialized a pencil.

As he watched, in stricken terror, the point of the pencil dropped to the tablecloth and slowly, precisely, it started to move. He stared, hypnotized, unbelieving, with the fingers of madness probing at his brain. The pencil wrote:

Wilson, you sold me out.

The man at the table tried to speak, tried to shriek, but his tongue and throat were dry and only harsh breath rattled in his mouth.

The pencil moved on mercilessly:

But you will pay. No matter where you go, I will find you. You cannot hide from me.

The pencil slowly lifted its point from the table and suddenly was gone, as if it had never been. Wilson, eyes wide and filled with terrible fear, stared at the black words on the cloth.

Wilson, you sold me out. But you will pay. No matter where you go, I will find you. You cannot hide from me.

The music pulsated in the room, the hum of conversation ran like an undertone, but Wilson did not hear. His entire consciousness was centered on the writing, the letters and the words that filled his soul with dread.

Something seemed to snap within him. The cold wind of terror reached out and struck at him. He staggered from the chair. His hand swept the wine gla.s.s from the table and it shattered into chiming shards.

"They can't do this to me!" he shrieked.

There was a silence in the room a silence of terrible accusation.

Everyone was staring at him. Eyebrows raised.

A waiter was at his elbow. "Do you feel ill, sir?"

And then, on unsteady feet, he was being led away. Behind him he heard the music once again, heard the rising hum of voices.

Someone set his hat on his head, was holding his coat. The cold air of the night struck his face and the doors sighed closed behind him.

"I'd take it easy going down the step, sir," counseled the doorman.

An aero-taxi driver held open the door of the cab and saluted.

"Where to, sir?"

Wilson stumbled in and stammered out his address. The taxi droned into the traffic lane.

Hands twitching, Wilson fumbled with the key, took minutes to open the door into his apartment. Finally the lock clicked and he pushed open the door. His questing finger found the wall switch. Light flooded the room.

Wilson heaved a sigh of relief. He felt safe here. This place belonged to him. It was his home, his retreat....

A low laugh, hardly more than a chuckle, sounded behind him. He whirled and for a moment, blinking in the light, he saw nothing. Then something stirred by one of the windows, gray and vague, like a sheet of moving fog.

As he watched, shrinking back against the wall, the grayness deepened, took the form of a man. And out of that mistiness a face was etched, a face that had no single line of humor in it, a bleak face with the fire of anger in the eyes.

"Manning!" shrieked Wilson. "Manning!" He wheeled and sprinted for the door, but the gray figure moved, too ... incredibly fast, as if it were wind-blown vapor, and barred his path to the door.

"Why are you running away?" Manning's voice mocked. "Certainly you aren't afraid of me."

"Look," Wilson whimpered, "I didn't think of what it meant. I just was tired of working the way Page made me work. Tired of the little salary I got. I wanted money. I was hungry for money."

"So you sold us out," said Manning.

"No," cried Wilson, "I didn't think of it that way. I didn't stop to think."

"Think now, then," said Manning gravely. "Think of this. No matter where you are, no matter where you go, no matter what you do, I'll always be watching you, I'll never let you rest. I'll never give you a minute's peace."

"Please," pleaded Wilson. "Please, go away and leave me. I'll give you back the money ... there's some of it left."