The choice of a cometary orbit was not a frivolous one. In the first place, it would have been necessary to wait more than one Earth year for Mars to be in the proper relation, orbit-wise, with the Hallelujah Node for the economical orbit; secondly, the travel time itself would be more than doubled - five hundred and eighty days for the economical orbit versus two hundred and sixty-nine days for the cometary orbit (a mere three days longer than the Luna-Mars trip).

Auxiliary tanks for single-H were fitted around the Stone's middle, giving her a fat and sloppy appearance, but greatly improving her mass-ratio for the ordeal. Port Pilot Jason Thomas supervised the refitting; the twins helped. Castor got up his nerve to ask Thomas how he had managed to conn the Stone in to a landing on their arrival. "Did you figure a ballis­tic before you came aboard, sir?"

Thomas put down his welding torch. "A ballistic? Shucks, no, son, I've been doing it so long that I know every little bit of space hereabouts by its freckles."

Which was all the satisfaction Cas could get out of him The twins talked it over and concluded that piloting must be something more than a mathematical science.

In addition to more space for single-H certain modifications were made inside the ship. The weather outside the orbit of Mars is a steady 'clear but cold'; no longer would they need reflecting foil against the Sun's rays. Instead one side of the ship was painted with carbon black and the capacity of the air-heating system was increased by two coils. In the control room a time-delay variable-baseline stereoscopic radar was installed by means of which they would be able to see the actual shape of the Hallelujah when they reached it.

All of which was extremely expensive and the Galactic Overlord had to work overtime to pay for it Hazel did not help with the refitting. She stayed in her room and ground out, with Lowell's critical help, more episodes in the gory but vir­tuous career of Captain John Sterling - alternating this activity with sending insulting messages and threats of blackmail and/or sit-down strike to her producers back in New York; she wanted an unreasonably large advance and she wanted it right now. She got it, by sending on episodes equal to the advance. She had to write the episodes in advance anyhow; this time the Rolling Stone would be alone, no liners comfortably near by. Once out of radio range of Mars, they would not be able to contact Earth again until Ceres was in range of the Stone's modest equipment. They were not going to Ceres but would be not far away; the Hallelujah was riding almost the same orbit somewhat ahead of that tiny planet.

The boost to a cometary orbit left little margin for cargo but what there was the twins wanted to use, undeterred by their father's blunt disapproval of the passengers-in-cold-sleep idea. Their next notion was to carry full outfits for themselves for meteor mining - rocket scooter, special suits, emergency shelter, keyed radioactive claiming stakes, centrifuge speegee tester, black lights, Geiger counters, prospecting radar, port­able spark spectroscope, and everything else needed to go quietly rock-happy.

Their father said simply, "Your money?"

"Of course. And we pay for the boost."

"Go ahead. Go right ahead. Don't let me discourage you. Any objections from me would simply confirm your preconceptions."

Castor was baffled by the lack of opposition. "What's the matter with it, Dad? You worried about the danger involved?"

"Danger? Heavens, no! It's your privilege to get yourselves killed in your own way. Anyhow, I don't think you will. You're young and you're both smart, even if you don't show it sometimes, and you're both in tiptop physical condition, and I'm sure you'll know your equipment."

"Then what is it?"

"Nothing. For myself, I long since came to the firm conclu­sion that a man can do more productive work, and make more money if this is his object, by sitting down with his hands in his pockets than by any form of physical activity. Do you happen to know the average yearly income of a meteor miner?"

"Well, no, but -"

"Less than six hundred a year."

"But some of them get rich!"

"Sure they do. And some make much less than six hundred a year; that's an average, including the rich strikes. Just as a matter of curiosity, bearing in mind that most of those miners are experienced and able, what is it that you two expect to bring to this trade that will enable you to raise the yearly average? Speak up; don't be shy."

"Doggone it, Dad, what would you ship?"

"Me? Nothing. I have no talent for trade. I'm going out for the ride - and to take a look at the bones of Lucifer. I'm begin­ning to get interested in planetology. I may do a book about it-"

"What happened to your other book?"

"I hope that isn't sarcasm, Cas. I expect to have it finished before we get there." He adjourned the discussion by leaving.

The twins turned to leave, found Hazel griamng at them. Castor scowled at her. "What are you smirking at, Hazel?"

"You two."

"Well... why shouldn't we have a whirl at meteor mining?"

"No reason. Go ahead; you can afford the luxury. But see here, boys, do you really want to know what to ship to make some money?"

"Sure!"

"What's your offer?"

"Percentage cut? Or flat fee? But we don't pay if we don't take your advice."

"Oh, rats! I'll give it to you free. If you get advice free, you won't take it and I'll be able to say, "I told you so!""

"You would, too."

"Of course I would. There's no warmer pleasure than being able to tell a smart aleck, "I told you so, but you wouldn't listen." Okay, here it is, in the form of a question, just like an oracle: Who made money in all the other big mining rushes of history?"

"Why, the chaps who struck it rich, I suppose."

"That's a laugh. There are so few cases of prospectors who actually hung on to what they had found and died rich that they stand out like supernovae. Let's take a famous rush, the California Gold Rush back in 1861- no, 1861 was something else; I forget. 1849, that was it - the 'Forty-niners. Read about 'em inhistory?"

"Some."

"There was a citizen named Sutter; they found gold on his place. Did it make him rich? It ruined him. But who did get rich?"

"Tell us, Hazel. Don't bother to dramatise it"

"Why not? I may put it in the show - serial numbers rubbed off, of course. I'll tell you: everybody who had something the miners had to buy. Grocers, mostly. Boy, did they get rich! Hardware dealers. Men with stamping mills, Everybody but the poor miner. Even laundries in Honolulu."

"Honolulu? But that's way out in the Pacific, off China somewhere."

"It was in Hawaii the last time I looked. But they used to ship dirty laundry from California clear to Honolulu to have it washed - both Ways by sailing ship. That's about like having your dirty shirts shipped from Marsport to Luna. Boys, if you want to make money, set up a laundry in the Hallelujah. But it doesn't have to be a laundry - just anything, so long as the miners want it and you've got it If your father wasn't a Puritan at heart, I'd set up a well-run perfectly honest gambling hall! That's like having a rich uncle."

The twins considered their grandmother's advice and went into the grocery business, with a few general store sidelines. They decided to stock only luxury foods, things that the miners would not be likely to have and which would bring highest prices per pound. They stocked antibiotics and surgical drugs and vitamins as well, and some lightweight song-and-story projectors and a considerable quantity of spools to go with them. Pollux found a supply of pretty-girl pictures, printed on thin stock in Japan and intended for calendars on Mars, and decided to take a flyer on them, since they didn't weigh much. He pointed out to Castor that they could not lose entirely, since they could look at them themselves.