In three weeks the permanent camp was ready for occupancy and the transport cleared of its cargo. The storerooms bulged with tools and supplies. Captain Doyle had moved his administrative offices underground, signed over his command to his first officer, and given him permission to proceed on 'duty assigned' -- in this case; return to Terra with a skeleton crew.Libby watched them take off from a vantage point on the hillside. An overpowering homesickness took possession of him. Would he ever go home? He honestly believed at the time that he would swap the rest of his life for thirty minutes each with his mother and with Betty.He started down the hill toward the tunnel lock. At least the transport carried letters to them, and with any luck the chaplain would be by soon with letters from Earth. But tomorrow and the days after that would be no fun. He had enjoyed being in the air gang, but tomorrow he went back to his squad. He did not relish that -- the boys in his squad were all right, he guessed, but he just could not seem to fit in.This company of the C.C.C. started on its bigger job; to pock-mark Eighty-eight with rocket tubes so that Captain Doyle could push this hundred-mile marble out of her orbit and herd her in to a new orbit between Earth and Mars, to be used as a space station -- a refuge for ships in distress, a haven for life boats, a fueling stop, a naval outpost.Libby was assigned to a heater in pit H-16. It was his business to carve out carefully calculated emplacements in which the blasting crew then set off the minute charges which accomplished the major part of the excavating. Two squads were assigned to H-16, under the general supervision of an elderly marine gunner. The gunner sat on the edge of the pit, handling the plans, and occasionally making calculations on a circular slide rule which hung from a lanyard around his neck.Libby had just completed a tricky piece of cutting for a three-stage blast, and was waiting for the blasters, when his phones picked up the gunner's instructions concerning the size of the charge. He pressed his transmitter button."Mr. Larsen! You've made a mistake!""Who said that?""This is Libby. You've made a mistake in the charge. If you set off that charge, you'll blow this pit right out of the ground, and us with it."Marine Gunner Larsen spun the dials on his slide rule before replying, "You're all het up over nothing, son. That charge is correct.""No, I'm not, sir," Libby persisted, "you've multiplied where you should have divided.""Have you had any experience at this sort of work?""No, sir."Larsen addressed his next remark to the blasters. "Set the charge."They started to comply. Libby gulped, and wiped his lips with his tongue. He knew what he had to do, but he was afraid. Two clumsy stiff-legged jumps placed him beside the blasters. He pushed between them and tore the electrodes from the detonator. A shadow passed over him as he worked, and Larsen floated down beside him. A hand grasped his arm."You shouldn't have done that, son. That's direct disobedience of orders. I'll have to report you." He commenced reconnecting the firing circuit.Libby's ears burned with embarrassment, but he answered back with the courage of timidity at bay. "I had to do it, sir. You're still wrong."Larsen paused and ran his eyes over the dogged face. "Well -- it's a waste of time, but I don't like to make you stand by a charge you're afraid of. Let's go over the calculation together."Captain Doyle sat at his ease in his quarters, his feet on his desk. He stared at a nearly empty glass tumbler."That's good beer, Blackie. Do you suppose we could brew some more when it's gone?""I don't know. Cap'n. Did we bring any yeast?""Find out, will you?" he turned to a massive man who occupied the third chair. "Well, Larsen, I'm glad it wasn't any worse than it was.""What beats me, Captain, is how I could have made such a mistake. I worked it through twice. If it had been a nitro explosive, I'd have known off hand that I was wrong. If this kid hadn't had a hunch, I'd have set it off."Captain Doyle clapped the old warrant officer on the shoulder. "Forget it, Larsen. You wouldn't have hurt anybody; that's why I require the pits to be evacuated even for small charges. These isotope explosives are tricky at best. Look what happened in pit A-9. Ten days' work shot with one charge, and the gunnery officer himself approved that one. But I want to see this boy. What did you say his name was?""Libby, A.J."Doyle touched a button on his desk. A knock sounded at the door. A bellowed "Come in!" produced a stripling wearing the brassard of Corpsman Mate-of-the-Deck."Have Corpsman Libby report to me.""Aye aye, sir."Some few minutes later Libby was ushered into the Captain's cabin. He looked nervously around, and noted Larsen's presence, a fact that did not contribute to his peace of mind. He reported in a barely audible voice, "Corpsman Libby, sir."The Captain looked him over. "Well, Libby, I hear that you and Mr. Larsen had a difference of opinion this morning. Tell me about it.""I -- I didn't mean any harm, sir.""Of course not. You're not in any trouble; you did us all a good turn this morning. Tell me, how did you know that the calculation was wrong? Had any mining experience?""No. sir. I just saw that he had worked it out wrong.""But how?"Libby shuffled uneasily. "Well, sir, it just seemed wrong -- it didn't fit.""Just a second, Captain. May I ask this young man a couple of questions?" It was Commander "Blackie" Rhodes who spoke."Certainly. Go ahead.""Are you the lad they call 'Pinkie'?"Libby blushed. "Yes, sir.""I've heard some rumors about this boy." Rhodes pushed his big frame out of his chair, went over to a bookshelf, and removed a thick volume. He thumbed through it, then with open book before him, started to question Libby."What's the square root of ninety-five?""Nine and seven hundred forty-seven thousandths." "What's the cube root?""Four and five hundred sixty-three thousandths.""What's its logarithm?""Its what, sir?""Good Lord, can a boy get through school today without knowing?"The boy's discomfort became more intense. "I didn't get much schooling, sir. My folks didn't accept the Covenant until Pappy died, and we had to.""I see. A logarithm is a name for a power to which you raise a given number, called the base, to get the number whose logarithm it is. Is that clear?"Libby thought hard. "I don't quite get it, sir.""I'll try again. If you raise ten to the second power -- square it -- it gives one hundred. Therefore the logarithm of a hundred to the base ten is two. In the same fashion the logarithm of a thousand to the base ten is three. Now what is the logarithm of ninety-five?'Libby puzzled for a moment. "I can't make it come out even. It's a fraction.""That's O.K.""Then it's one and nine hundred seventy-eight thousandths -- just about."Rhodes turned to the Captain. "I guess that about proves it, sir."Doyle nodded thoughtfully. "Yes, the lad seems to have intuitive knowledge of arithmetical relationships. But let's see what else he has.""I am afraid we'll have to send him back to Earth to find out properly."Libby caught the gist of this last remark. "Please, sir, you aren't going to send me home? Maw 'ud be awful vexed with me.""No, no, nothing of the sort. When your time is up, I want you to be checked over in the psychometrical laboratories. In the meantime I wouldn't part with you for a quarter's pay. I'd give up smoking first. But let's see what else you can do."In the ensuing hour the Captain and the Navigator heard Libby: one, deduce the Pythagorean proposition; two, derive Newton's laws of motion and Kepler's laws of ballistics from a statement of the conditions in which they obtained; three, judge length, area, and volume by eye with no measurable error. He had jumped into the idea of relativity and nonrectilinear space-time continua, and was beginning to pour forth ideas faster than he could talk, when Doyle held up a hand."That's enough, son. You'll be getting a fever. You run along to bed now, and come see me in the morning. I'm taking you off field work.""Yes, sir.""By the way, what is your full name?""Andrew Jackson Libby, sir.""No, your folks wouldn't have signed the Covenant. Good night.""Good night, sir."After he had gone, the two older men discussed their discovery."How do you size it up, Captain?""Well, he's a genius, of course -- one of those wild talents that will show up once in a blue moon. I'll turn him loose among my books and see how he shapes up. Shouldn't wonder if he were a page-at-a-glance reader, too.""It beats me what we turn up among these boys -- and not a one of 'em any account back on Earth."Doyle nodded. "That was the trouble with these kids. They didn't feel needed."