to slap at the "mosquito" the barb could just as easily have buried itself in his skull.

Corriston hesitated for an instant, his eyes on the barred window and the faint glow beyond. Then his gaze passed to the wall switch. He decided against switching on the light immediately. He stooped low and moved quickly to the window, taking care to keep his head well below the sill.

For a moment he listened, his every nerve alert. There was no stir of movement in the darkness beyond the sill, nothing at all to indicate that someone was crouching there.

Finally, with an almost foolhardy recklessness, he raised his head and stared out between the bars. He could see right across to the wall opposite. The wall was less than eight feet away, and the space between the wall and his cell appeared to be unoccupied. This did not surprise him.

It was utterly silly to think that a man intent on willful murder would have lingered for any great length of time in so narrow a space. After having shot his bolt, his immediate concern would have been to get away as quickly as possible.

No, definitely, the man was gone, and if he had more barbs to release he would choose another time and place.

Even then Corriston did not switch on the light. He had no particular desire to examine the wood-embedded barb in a bright light. He could see it clearly enough from where he stood. It was exactly like the barb which had sealed the lips of that blabbermouth Clakey.

Corriston went back to his cot and sat down. He told himself it would be highly dangerous to leave the cell and give the killer another chance. He had saved himself by refusing to slap a non-existent mosquito. But in the shadows of the Station there would be no mosquitoes—non-existent or otherwise. The killer would simply crouch in shadows, await his chance, and take careful aim.

What he had to do was find Miss Ramsey, and prove his sanity. If he stayed in the cell, the shadows would continue to deepen about him, would become intolerable, and perhaps even drive him to the verge of actual madness.

He had to convince the killer that he couldn't be silenced easily and perhaps not at all.

Corriston stood up. He ran his hands down his body, taking pride in its muscular solidity, its remarkable integrity under strain. He still felt lithe and confident; his physical vitality was unimpaired.

He had really known all along that he would be leaving the cell. On Earth you could dodge into a narrow alley between tall buildings or lean on a stroller platform and be carried underground so fast that your pursuers would be left blank-faced. If he stayed alert he could do the same thing on the Station, even though there were no moving pavements to leap upon. Quite possibly he could even slip out unnoticed. They might not even be watching the cell door because he had behaved himself so well up to now. Psycho-cases were permitted to roam, but if they stayed in their cells precautions would naturally be relaxed in their favor.

Corriston now was about to develop a sudden, unanticipated impulse to roam. The fact that he was completely sane gave him an edge over the space-shocked recruits. There is nothing quite so terrifying to a man who doubts his own sanity than the thought that unseen eyes are keeping tabs on him. He feels guilty and acts guilty and almost invariably his caution deserts him.

Corriston was quite sure that he could carry it off, even if he felt eyes boring into his back the instant he left the cell. He'd simply bide his time and seize the first opportunity which presented itself.

Actually, it was easier than he'd imagined it could be. He simply opened the cell door, walked out; and there was no one in sight to observe him. So far, so good. The corridor outside was completely deserted, and when he reached the end of it there was still no one.

He turned left into a large, square reception room and crossed it without hurrying, his shoulders held straight. Photoelectric eyes? Yes, possibly, but he had no intention of letting the thought worry him. If he were being watched mechanically, there was nothing he could do about it and somehow he didn't think that he had crossed any photoelectric beams. Certainly no doors had swung open or closed behind him, and photoelectric alarm system without visible manifestations could be dismissed as a not too likely possibility.

When Corriston emerged in the glass-encased, wide-view observation promenade on the Station's Second Level, he was no longer alone. On all sides men and women jostled him, walking singly and in pairs, in uniform and in civilian clothes, or hurrying off in dun-gray, space-mechanic anonymity.

The promenade was crowded almost to capacity and yet the men and women seemed mere walking dots scattered at random beneath the immense structures of steel and glass which walled them in. A feeling of unreality came upon Corriston as he stared upward. He deliberately moderated his stride, as if fearful that a too rapid movement in any one direction might send him spinning out into space with a glass-shattering impetus which he would be powerless to control.

It was an illogical fear and yet he could not entirely throw it off, and he did not seriously try. It was not nearly as important as the possibility that he might be being followed. There was no one behind him who looked in the least suspicious, and no one in front of him either. But how could he be completely sure?

The answer was that he couldn't. He had to trust his instincts, and so far they had given him every assurance that he was moving in a free, independent orbit of his own, completely unobserved.

And then, quite suddenly, he ceased to move at all.

Something quite startling was taking place throughout the length and breadth of the observation promenade. The men in uniform were exchanging alarmed glances and departing in haste. The civilians were crowding closer to the panes. They were collecting in awestruck groups of blinding light crisscrossed high above their heads.

They were all looking in one direction, but a few of them had been taken so completely by surprise that they stood motionless in the middle of the promenade. Corriston was one of the motionless ones, but his eyes were quick to seek out the nearest viewpane.

At first he thought that a gigantic meteor had appeared suddenly out of the stellar dark and was rushing straight toward the Station with a velocity so great as to be almost unimaginable.

Then he realized that it wasn't a meteor. It was a spaceship. And it wasn't rushing straight toward the Station. It had either bypassed or encircled the Station and passed beyond it, for it was now heading out into space again. He could see the long, bright trail left by its rocket jets, the diffuse incandescence in its wake.