McNeil had satisfied himself by careful calculation that four cigarettes a day would make no measurable difference whatsoever to the ship's oxygen endurance, whereas they would make all the difference in the world to his own nerves and hence indirectly to Grant's.
But it was no use explaining this to Grant. So he had smoked in private and with a self-control he found agreeably, almost voluptuously, surprising. It was sheer bad luck that Grant had detected one of the day's four cigarettes.
For a man who had only at that moment talked himself into murder, Grant's actions were remarkably methodical. Without hesitation, he hurried back to the control room and opened the medicine chest with its neatly labeled compartments, designed for almost every emergency that could occur in space.
Even the ultimate emergency had been considered, for there behind its retaining elastic bands was the tiny bottle he had been seeking, the image of which had been lying hidden far down in the unknown depths of his mind through all these days. It bore a white label carrying a skull-and-crossbones, and beneath them the words: Approx. one-half gram will cause painless and almost instantaneous death.
The poison was painless and instantaneous-that was good. But even more important was a fact unmentioned on the label. It was also tasteless.
The contrast between the meals prepared by Grant and those organized with considerable skill and care by McNeil was striking. Anyone who was fond of food and who spent a good deal of his life in space usually learned the art of cooking in self-defense. McNeil had done this long ago.
To Grant, on the other hand, eating was one of those necessary but annoying jobs which had to be got through as quickly as possible. His cooking reflected this opinion. McNeil had ceased to grumble about it, but he would have been very interested in the trouble Grant was taking over this particular meal.
If he noticed any increasing nervousness on Grant's part as the meal progressed, he said nothing. They ate almost in silence, but that was not unusual for they had long since exhausted most of the possibilities of light conversation. When the last dishes-deep bowls with in-turned rims to prevent the contents drifting out-had been cleared away, Grant went into the galley to prepare the coffee.
He took rather a long time, for at the last moment something quite maddening and quite ridiculous happened. He suddenly recalled one of the film classics of the last century in which the fabulous Charlie Chaplin tried to poison an unwanted wife-and then accidentally changed the glasses.
No memory could have been more unwelcome, for it left him shaken with a gust of silent hysteria. Poe's Imp of the Perverse, that demon who delights in defying the careful canons of self-preservation, was at work and it was a good minute before Grant could regain his self-control.
He was sure that, outwardly at least, he was quite calm as he carried in the two plastic containers and their drinking tubes. There was no danger of confusing them, for the engineer's had the letters MAC painted boldly across it.
At the thought Grant nearly relapsed into psychopathic giggles but just managed to regain control with the somber reflection that his nerves must be in even worse condition than he had imagined.
He watched, fascinated, though without appearing to do so, as McNeil toyed with his cup. The engineer seemed in no great hurry and was staring moodily into space. Then he put his lips to the drinking tube and sipped.
A moment later he spluttered slightly-and an icy hand seemed to seize Grant's heart and hold it tight. Then McNeil turned to him and said evenly, "You've made it properly for once. It's quite hot."
Slowly, Grant's heart resumed its interrupted work. He did not trust himself to speak, but managed a noncommittal nod. McNeil parked the cup carefully in the air, a few inches away from his face.
He seemed very thoughtful, as if weighing his words for some important remark. Grant cursed himself for having made the drink so hot-that was just the sort of detail that hanged murderers. If McNeil waited much longer he would probably betray himself through nervousness.
"I suppose," said McNeil in a quietly conversational sort of way, "it has occurred to you that there's still enough air to last one of us to Venus?"
Grant forced his jangling nerves under control and tore his eyes away from that hypnotic cup. His throat seemed very dry as he answered, "It-it had crossed my mind."
McNeil touched his cup, found it still too hot and continued thoughtfully, "Then wouldn't it be more sensible if one of us decided to walk out of the airlock, say-or to take some of the poison in there?" He jerked his thumb toward the medicine chest, just visible from where they were sitting.
Grant nodded.
"The only trouble, of course," added the engineer, "is to decide which of us will be the unlucky one. I suppose it would have to be by picking a card or in some other quite arbitrary way."
Grant stared at McNeil with a fascination that almost outweighed his mounting nervousness. He had never believed that the engineer could discuss the subject so calmly. Grant was sure he suspected nothing. Obviously McNeil's thoughts had been running on parallel lines to his own and it was scarcely even a coincidence that he had chosen this time, of all times, to raise the matter.
McNeil was watching him intently, as if judging his reactions.
"You're right," Grant heard himself say. "We must talk it over."
"Yes," said McNeil quite impassively. "We must." Then he reached for his cup again, put the drinking tube to his lips and sucked slowly.
Grant could not wait until he had finished. To his surprise the relief he had been expecting did not come. He even felt a stab of regret, though it was not quite remorse. It was a little late to think of it now, but he suddenly remembered that he would be alone~ in the Star Queen, haunted by his thoughts, for more than three weeks before rescue came.
He did not wish to see McNeil die, and he felt rather sick. Without another glance at his victim he launched himself toward the exit.
Immovably fixed, the fierce sun and the unwinking stars looked down upon the Star Queen, which seemed as motionless as they. There was no way of telling that the tiny dumbbell of the ship had now almost reached her maximum speed and that millions of horsepower were chained within the smaller sphere, waiting for the moment of its release. There was no way of telling, indeed, that she carried any life at all.
An airlock on the night-side of the ship slowly opened, letting a blaze of light escape from the interior. The brilliant circle looked very strange hanging there in the darkness. Then it was abruptly eclipsed as two figures floated out of the ship.
One was much bulkier than the other, and for a rather important reason-it was wearing a space-suit. Now there are some forms of apparel that may be worn or discarded as the fancy pleases with no other ill-effects than a possible loss of social prestige. But spacesuits are not among them.
Something not easy to follow was happening in the darkness. Then the smaller figure began to move, slowly at first but with rapidly mounting speed. It swept out of the shadow of the ship into the full blast of the sun, and now one could see that strapped to its back was a small gas-cylinder from which a fine mist was jetting to vanish almost instantly into space.
It was a crude but effective rocket. There was no danger that the ship's minute gravitational pull would drag the body back to it again.
Rotating slightly, the corpse dwindled against the stars and vanished from sight in less than a minute. Quite motionless, the figure in the airlock watched it go. Then the outer door swung shut, the circle of brilliance Vanished and only the pale Earthlight still glinted on the shadowed wall of the ship.
Nothing else whatsoever happened for twenty-three days.
The captain of the Hercules turned to his mate with a sigh of relief.
"I was afraid he couldn't do it. It must have been a colossal job to break his orbit single-handed-and with the air as thick as it must be by now. How soon can we get to him?"
"It will take about an hour. He's still got quite a bit of eccentricity but we can correct that."
"Good. Signal the Leviathan and Titan that we can make contact and ask them to take off, will you? But I wouldn't drop any tips to your news commentator friends until we're safely locked."
The mate had the grace to blush. "I don't intend to," he said in a slightly hurt voice as he pecked delicately at the keys of his calculator. The answer that flashed instantly on the screen seemed to displease him.
"We'd better board and bring the Queen down to circular speed ourselves before we call the other tugs," he said, "otherwise we'll be wasting a lot of fuel. She's still got a velocity excess of nearly a kilometer a second."
"Good idea-tell Leviathan and Titan to stand by but not to blast until we give them the new orbit."
While the message was on its way down through the unbroken cloudbanks that covered half the sky below, the mate remarked thoughtfully, "I wonder what he's feeling like now?"
"I can tell you. He's so pleased to be alive that he doesn't give a hoot about anything else."
"Still, I'm not sure I'd like to have left my shipmate in space so that I could get home."
"It's not the sort of thing that anyone would like to do. But you heard the broadcast-they'd talked it over calmly and the loser went out of the airlock. It was the only sensible way."
"Sensible, perhaps-but it's pretty horrible to let someone else sacrifice himself in such a cold-blooded way so that you can live."
"Don't be a ruddy sentimentalist. I'll bet that if it happened to us you'd push me out before I could even say my prayers."
"Unless you did it to me first. Still, I don't think it's ever likely to happen to the Hercules. Five days out of port's the longest we've ever been, isn't it? Talk about the romance of the spaceways!"
The captain didn't reply. He was peering into the eyepiece of the navigating telescope, for the Star Queen should now be within optical range. There was a long pause while he adjusted the vernier controls. Then he gave a little sigh of satisfaction.