BUT where’s the catch? You wonder. Thirteen containers, each good for three days if you’re careful, add up to thirty-nine.
You don’t have to ask it aloud. Camelon thinks, “One of the containers is poisoned. There is an odorless undetectable gas that will evaporate with the oxygen. It is sufficiently poisonous to kill ten men of your weight and resistance, of your general metabolism. There is no way to tell it from the other jars without extremely special equipment and chemical knowledge beyond yours. The day you ’ open that container you die.”
“Fine,” you say. “But how does that give me a chance if I have to use all thirteen containers in order to live through?”
“There is a slight possibility—one which we have calculated very carefully —that you can survive on twelve containers of oxygen. If you can and if you choose the proper twelve—which you have one chance out of thirteen of doing —you will survive. The parley of the two chances adds up to one chance out of a thousand. We leave now. My companions await me in our ship.”
He doesn’t wish you good-bye and you don’t wish him good-bye either. You watch the inner door of the airlock close.
You go over and look at the thirteen containers of oxygen and they all look alike. The air is very thin and hard to breathe. You’re going to have to open one of them quite soon. The wrong one? The one than contains enough poison to kill ten men?
Maybe it would be better if you pick the wrong one first and get it over with. The poison is odorless and undetectable —maybe it’s painless too. You wish you’d wondered that while he was still here; he’d have answered it for you. Probably it is painless—or is that only wishful thinking?
You look around the rest of the place. They haven’t left a thing of value except those thirteen containers and the food and water. It doesn’t look like much food and water for that long a period. But it probably is enough, barely, if you ration it carefully. Probably they feared if they left any surplus water you might figure some way to get the oxygen out of it. They were wrong on that but they didn’t take any chances—except the thousand-to-one chance.
You’re panting, breathing like an asthmatic. You reach for a container to open it. If you do there’s one chance out of thirteen that you’ll be dead in hours, maybe in minutes. They didn’t tell you either how fast-acting the poison is.
You pull your hand back. You don’t want to take even one chance out of thirteen of dying until you’ve had a chance to think carefully. You go back to the cot and lie down to think because you remember that every muscular motion you make cuts your chances.
Have they missed anything, anything at all? The oxygen tank on back of your space-suit. You sit up suddenly and look and see that the space-suit itself is gone. There’s no advantage to the airlock— the air that enters it when you pull the lever comes from-this room. And the lock is empty now since it was last used for a departure.
The hydroponic garden is gone. So are the emergency tanks of oxygen that were in the storeroom in case of failure of the plants. You realize that you’ve got up and are wandering around again and you sit down. You cut your chances with every step you take.
One chance in a thousand—if you can use only twelve containers of oxygen there’s—you figure it out mentally— there must be one chance in about seventy-seven that you’ll live. That’s what, they must have figured. One chance in seventy-seven parlayed against one in thirteen is about one in a thousand.
But if you could use all thirteen containers your chances would be good, better than even. Not quite, a certainty because there-is always the possibility that something would go wrong, such as your losing your will power on rationing the food—or, more likely, the water—and dying of hunger or thirst in the last day or two.
You look for something to write with to see if they , made any mistake on the hypnotic block. You can’t find anything but you find out it doesn’t matter. You’ve got a finger, haven’t you? You try to write your name on the wall with your finger. You can’t. You know your name all right—Bob Thayer. But you haven’t the faintest idea how to write it.
You could talk the message if you had a recording machine, but you haven’t a recording machine or any materials which, by any stretch of the imagination, would let you make one. You’ve got only your brain. You sit down and use it.
YOU forget to wind your watch and then, because of the pain, you wind it too tight and break or jam the spring and you’ve lost track of time and then comes the time when you find that half of your supplies are gone and you hope that half of the thirty-nine days is gone too.
And then again you’re sick and delirious and part of the time you think you’re back on Earth and that you’ve just had a nightmare about creatures from a place called Tharngel and you dreamed within the nightmare that you were playing poker on the Moon and that you won.
Pain, thirst, hunger, struggle for breath, nightmare. And then one day you eat the last of the food and drink the last of the water and you wonder whether it’s the thirty-first day or the thirty-ninth and you lie down again and wait to find out.
And you sleep and in your dream you hear an earthshaking racket that could be the landing of the Relief except that you know you’re dreaming and in your dream the air gets even thinner as air rushes from the dome into the airlock and the airlock opens and Captain Thorkelsen is standing there beside you and you say, “Hi, Captain,” weakly and wake up to find out that you weren’t really asleep and then you black out. ‘
And when you come around again,, there is good breatheable air in the dome and there is food waiting for you to eat and water waiting for you to drink. And all four of them from the Relief are standing around watching you anxiously.
Thorkelsen grins down at you. “What have you been doing? Where are all the books and equipment ? What happened?”
“Got in a poker game,” you tell him. Your throat is dry, still almost too dry to talk, but you drink some water—carefully, a sip at a time.
And then you’re telling the story, a bit at a time, as you sip more water and eat a little and you begin to feel almost human again.
And from the way they listen and the way they watch you, you know that they believe it—that they’d believe you even if it weren’t for the evidence around them. And that Earth will believe and that everything’s all right, that forty years is a long time even to develop a new science when all of Earth is working at it. And you’ve still got the clues to give them a start and your gamble paid off. You won the poker game after all.
You get tired after a while and have to stop talking. Thorkelsen looks at you wonderingly. He says, “But, Good Lord, man, how did you do it? All those oxygen containers—if that’s what they were —are plumb empty. And you say enough poison to kill ten men was in one of them. You look like you’ve lost thirty pounds weight and you look like you’ll need a month’s rest before you can walk again but you’re alive. Did they miscalculate or what?”
You can’t keep your eyes open any longer—you’ve got to sleep. But maybe you can take time to explain.
“Simple, Cap,” you tell him. “Each container held enough oxygen for one man for three days and one of them also contained enough poison to kill ten men. But there were thirteen containers, so I opened them all and mixed them together, and then put them back and opened one approximately every three days. So every minute, from the opening of the first one, there’s been ten-thirteenths of enough poison in the air to kill a man. For thirty-nine days I’ve been breathing almost enough poison to kill me.