“He must’ve picked up my report. He didn’t dump his radar. He stayed in the cloud bank. When the jet came for him—spotting him with its night-fighter stuff—he tried to ram. Tried for a collision. So the jet gave him the works. Blew him apart. Couldn’t make him land. Maybe they’ll pick up something from the wreckage.”

Joe wet his lips.

“I—saw what happened,” he said. “He tried to smash us with rockets. Where’d he get them? How were they smuggled in?”

The co-pilot shrugged. “Maybe smuggled in. Maybe stolen. They coulda been landed from a sub anywhere on a good many thousand miles of coast. They coulda been hauled anywhere in a station wagon. The plane was a private-type ship. Plenty of them flying around. It could’ve been bought easily enough. All they’d need would be a farm somewhere where it could land and they could strap on a rocket rack and put in a radar. And they’d need information. Probably be a good lead, this business. Only just so many people could know what was coming on this ship, and what course it was flying, and so on. Security will have to check back from that angle.”

A shadow fell upon the transport ship. A jet shot past from above it. It waggled its wings and changed course.

“We’ve got to land and be checked for damage,” said the co-pilot negligently. “These guys will circle us and lead the way—as if we needed it!”

Joe subsided. He still had in his mind the glamorous and infinitely alluring picture of the Space Platform floating grandly in its orbit, with white-hot sunshine on it and a multitude of stars beyond. He had been completely absorbed in that aspect of the job that dealt with the method of construction and the technical details by which the Platform could be made to work.

Now he had a side light on the sort of thing that has to be done when anything important is achieved. Figuring out how a thing can be done is only part of the job. Overcoming the obstacles to the apparently commonplace steps is nine-tenths of the difficulty. It had seemed to him that the most dramatic aspect of building the Space Platform had been the achievement of a design that would work in space, that could be gotten up into space, and that could be lived in under circumstances never before experienced. Now he saw that getting the materials to the spot where they were needed called for nearly as much brains and effort. Screening out spies and destructionists—that would be an even greater achievement!

He began to feel a tremendous respect and solicitude for the people who were doing ordinary jobs in the building of the Platform. And he worried about his own share more than ever.

Presently the transport ship sank toward the clouds. It sped through them, stone-blind from the mist. And then there was a small airfield below, and the pilot and co-pilot began a pattern of ritualistic conversation.

“Pitot and wing heaters?” asked the pilot.

The co-pilot put his hand successively on two controls.

“Off.”

“Spark advance?”

The co-pilot moved his hands.

“Take-off and climb?” said the co-pilot.

“Blowers?”

“Low.”

“Fuel selectors?”

The co-pilot moved his hands again to the appropriate controls, verifying that they were as he reported them.

“Main on,” he said matter-of-factly, “crossfeed off.”

The transport plane slanted down steeply for the landing field that had looked so small at first, but expanded remarkably as they drew near.

Joe found himself frowning. He began to see how really big a job it was to get a Space Platform even ready to take off for a journey that in theory should last forever. It was daunting to think that before a space ship could be built and powered and equipped with machinery there had to be such wildly irrelevant plans worked out as a proper check of controls for the piston-engine ships that flew parts to the job. The details were innumerable!

But the job was still worth doing. Joe was glad he was going to have a share in it.

2

It was a merely misty day. The transport plane stood by the door of a hangar on this military field, and mechanics stood well back from it and looked it over. A man crawled over the tail assembly and found one small hole in the fabric of the stabilizer. A shell fragment had gone through when the war rockets exploded nearby. The pilot verified that the fragment had hit no strengthening member inside. He nodded. The mechanic made very neat fabric patches over the two holes, upper and lower. He began to go over the fuselage. The pilot turned away.

“I’ll go talk to Bootstrap,” he told the co-pilot. “You keep an eye on things.”

“I’ll keep two eyes on them,” said the co-pilot.

The pilot went toward the control tower of the field. Joe looked around. The transport ship seemed very large, standing on the concrete apron with its tricycle landing gear let down. It curiously resembled a misshapen insect, standing elaborately high on inadequate supporting legs. Its fuselage, in particular, did not look right for an aircraft. The top of the cargo section went smoothly back to the stabilizing fins, but the bottom did not taper. It ended astern in a clumsy-looking bulge that was closed by a pair of huge clamshell doors, opening straight astern. It was built that way, of course, so that large objects could be loaded direct into the cargo hold, but it was neither streamlined nor graceful.

“Did anything get into the cargo hold?” asked Joe in sudden anxiety. “Did the cases I’m with get hit?”

After all, four rockets had exploded deplorably near the ship. If one fragment had struck, others might have.

“Nothing big, anyhow,” the co-pilot told him. “We’ll know presently.”

But examination showed no other sign of the ship’s recent nearness to destruction. It had been overstressed, certainly, but ships are built to take beatings. A spot check on areas where excessive flexing of the wings would have shown up—a big ship’s wings are not perfectly rigid: they’d come to pieces in the air if they were—presented no evidence of damage. The ship was ready to take off again.

The co-pilot watched grimly until the one mechanic went back to the side lines. The mechanic was not cordial. He and all the others regarded the ship and Joe and the co-pilot with disfavor. They worked on jets, and to suggest that men who worked on fighter jets were not worthy of complete confidence did not set well with them. The co-pilot noticed it.

“They think I’m a suspicious heel,” he said sourly to Joe, “but I have to be. The best spies and saboteurs in the world have been hired to mess up the Platform. When better saboteurs are made, they’ll be sent over here to get busy!”

The pilot came back from the control tower.

“Special flight orders,” he told his companion. “We top off with fuel and get going.”

Mechanics got out the fuel hose, dragging it from the pit. One man climbed up on the wing. Other men handed up the hose. Joe was moved to comment, but the co-pilot was reading the new flight instructions. It was one of those moments of inconsistency to which anybody and everybody is liable. The two men of the ship’s crew had it in mind to be infinitely suspicious of anybody examining their ship. But fueling it was so completely standard an operation that they merely stood by absently while it went on. They had the orders to read and memorize, anyhow.

One wing tank was full. A big, grinning man with sandy hair dragged the hose under the nose of the plane to take it to the other wing tank. Close by the nose wheel he slipped and steadied himself by