"That's what I meant. Will you finish in time?"

Conrad sighed. "I wish I knew."

The pressure of time sat heavily on all of them. In their mess hall they had set up a large chart showing Earth, Sun, Venus, and Mars, each in its proper position. At lunch each day the markers were moved along the scribed orbits, the Earth by one degree, Venus a bit more, Mars by only half a degree and a trifle.

A long dotted line curved from a point on Earth's orbit to a rendezvous with Mars-their best estimate of the path and arrival date of the Federation task force. The departure date was all they knew with certainty; the trajectory itself and the arrival date were based on the relative positions of the two planets and what was believed to be the maximum performance of any Federation ship, assuming refueling in parking orbit around Earth.

For a rocket ship some orbits are possible, some are impossible. A military ship in a hurry would not, of course, use the economical doubly-tangent ellipse; such a trip from Earth to Mars would require 258 Earth days. But, even using hyperboloids and wasting fuel, there are severe limits to how quickly a reaction-driven ship can make an interplanetary voyage.

An Earth calendar hung beside the chart; near it was a clock showing Earth Greenwich time. Posted near these was a figure, changed each time the clock read twenty-four hundred, the number of days till M-day-by their best estimate, now only thirty-nine.

Don was enjoying a combat soldier's paradise-hot food sharp on the hour, well cooked and plenty of it, all the sack time he cared to soak up, clean clothes, clean skin, no duties and no hazards. The only trouble was that he soon grew to hate it.

The intense activity around him shamed him into wanting to help-and try to help he did-until he found out that he was being given make-work to shut him up. Actually there was nothing he could do to help; the sweating specialists, trying their level best to haywire improbable circuits into working, had no time to waste on an untrained assistant. He gave up and went back to loafing, found that he could sleep all right in the afternoons but that the practice kept him awake at night.

He wondered why he could not enjoy so pleasant a leave. It was not that-he was worried about his parents.

Yes, he was! Though they had grown dim in his memory his conscience was biting him that he was doing nothing helpful for them. That was why he wanted to get out, away from here where he could do no good, back to his outfit, back to his trade-back to where there was nothing to worry about between scrambles-and plenty to worry about then. With the blackness around you and the sound of your mate's breathing on your right and the same for the man on your left-the slow move forward, trying to feel out what dirty tricks the Greenie techs had thought of this time to guard their sleep... the quick strike-and the pounding drive back to the boat with nothing to guide you through the dark but the supersonics in your head bones

He wanted to go back.

He went to see Phipps about it, sought him out in his office. "You, eh? Have a cigarette."

"No, thanks."

"Real tobacco-none of your `crazy weed.'"

"No, thanks, I don't use 'em."

"Well, maybe you've got something. The way my mouth tastes these mornings-" Phipps lit up himself, sat back and waited.

Don said, "Look-you're the boss around here."

Phipps exhaled, then said carefully, "Let's say I'm the coordinator. I certainly don't try to boss the technical work."

Don brushed it aside. "You're the boss for my purposes. See here, Mr. Phipps, I feel useless around here. Can you arrange to get me back to my outfit?"

Phipps carefully made a smoke ring. "I'm sorry you feel that way. I could give you work to do. You could be an executive assistant to me."

Don shook his head. "I've had enough of `pick up sticks and lay them straight. I want real work-my own work. I'm a soldier and there's a war going on-that's where I belong. Now when can I get transportation?"

"You can't."

"Huh?"

"Mr. Harvey, I can't let you go; you know too much. If you had turned over the ring without asking questions, you could have gone back to your outfit the next hour-but you had to know, you had to know everything. Now we don't dare risk your capture. You know the Greenies put every prisoner through full interrogation; we can't dare risk that-not yet."

"But-Dog take it, sir, I'll never be captured! I made up my mind about that a long time ago."

Phipps shrugged. "If you get yourself killed, that's all right. But we can't be sure of that, no matter how resolute you are. We can't risk it; there's too much at stake."

"You can't hold me here! You have no authority over me!"

"No. But you can't leave."

Don opened his mouth, closed it, and walked out.

He woke up the next morning determined to do something about it. But Dr. Conrad was up before he was and stopped to make a suggestion before he left. "Don?"

"Yeah, Rog?"

"If you can tear yourself out of that sack, you might come around to the power lab this morning. There will be something worth looking at-I think."

"Huh? What? What time?"

"Oh, say about nine o'clock."

Don showed up, along with apparently every human in the place and about half of Sir Isaac's numerous family. Roger Conrad was in charge of the demonstration. He was busy at a control console which told the uninstructed observer nothing. He busied himself with adjustments, looked up and said, "Just keep your eyes on the birdie, folks-right over that bench." He pressed a key.

There flicked into being over the bench, hanging in the air unsupported, a silvery ball some two feet across. It seemed to be a perfect sphere and a perfect reflector and, more than anything else in the world, it made Don think of a Christmas tree ornament. Conrad grinned triumphantly. "Okay, Tony-give it the ax!"

Tony Vincente, the most muscular of the laboratory crew, picked up a broadbladed ax he had ready. "How would you like it split-up and down, or sideways?"

"Suit yourself."

Vincente swung the ax over his head and brought it down hard.

It bounced off.

The sphere did not quiver, nor was there any mar on its perfect mirror surface. Conrad's boyish grin got even wider. "End of act one," he announced and pressed another button. The sphere disappeared, left nothing to show where it had been.

Conrad bent over his controls. "Act two," he announced. "We now cancel out half the locus. Stand clear of the bench." Shortly he looked up. "Ready! Aim! Fire!" Another shape took being, a perfect sphere otherwise like the last. Its curved outer surface was faced up. "Stick the props in, Tony."

"Just a sec, while I light up." Vincente lit a cigarette, puffed it vigorously, then propped it in an ash tray and slid it under the half globe. Conrad again manipulated his controls; the shape descended, rested on the bench, covering the burning cigarette on its tray. "Anybody want to try the ax on it, or anything else?" asked Conrad.

Nobody seemed anxious to tamper with the unknown. Conrad again operated his board and the silver bowl lifted. The cigarette still smoldered in the tray, unaffected. "How," he asked, "would you like to put a lid like that over the Federation's capital at Bermuda-aiid leave it in place until they decided to come to terms?"

The idea quite evidently met with unanimous approval. The members of the Organization present were all, or almost all, citizens of Venus, emotionally involved in the rebellion no matter what else they were doing. Phipps cut through the excited comment with a question. "Dr. Conrad-would you give us a popular explanation of what we have seen? Why it works, I mean; we can guess at its enormous potentials."

Conrad's face got very serious. "Mmm... Chief, perhaps it would be clearest to say that the fasarta modulates the garbab in such a phase relationship that the thrimaleen is forced to bast-or, to put it another way, somebody loosed mice in the washroom. Seriously, there is no popular way to explain it. If you were willing to spend five hard years with me, working up through the math, I could probably bring you to the same level of ignorance and confusion that I enjoy. Some of the tensor equations involved are, to put it mildly, unique. But the instructions were clear enough and we did it."