by Hal Clement
“Here, too?” he asked. “The door on my side will never open while this ship is whole. Someone wanted to keep something either outside or inside that section.”
“Probably in, since the welding was done from outside,” replied Preble. “I’d like to know what it was. It would probably give us an idea of the reason for the desertion of this ship. Did you go down to the lower level?”
“Not yet. We might as well go together—if one side is sealed, the other probably will be, too. Come on.”
They were still on the left-hand ramp, so it was on this side that they descended. A glance at the door here showed that, at least, it was not welded; the pressure of a hand showed it to be unlocked. The two men found themselves at the end of a corridor similar in all respects to the one above, except that it came to a dead end to the right of the door instead of continuing on into the central chamber. It was pitch-dark, except for the reflections of the hand lights on the polished metal walls and along either side were doors, perhaps a trifle larger than most of the others on the ship. Many of these were ajar, others closed tightly; and by common consent the men stepped to the nearest of the former.
The room behind it proved similar in size to those above, but it lacked the articles which the men had come to look upon as the furniture of the long-dead crew. It was simply a bare, empty cubicle.
The other chambers, quickly examined, showed no striking difference from the first. Several contained great stacks of metal ingots, whose inertia and color suggested platinum or iridium; all were thickly coated with dust, as was the floor of the corridor. Here, too, there must have been organic materials, whether crew or cargo none could tell, which had slowly rotted away while the amazingly tight hull held stubbornly to its air. The makers of the ship had certainly been superb machinists—no vessel made by man would have held atmosphere more than a few months, without constant renewal.
“Have you noticed that there is nothing suggestive of a lock on any of these doors?” asked Preble, as they reached the blank wall which shut them off from the engine room in front.
“That’s right,” agreed Stevenson. “The engine-room port was the only one which had any obvious means of fastening. You’d think there would be need to hold them against changes in acceleration, if nothing else.”
He went over to the nearest of the doors and with some care examined its edge, which would be hidden when it was closed; then he beckoned to Preble. Set in the edge, almost invisible, was a half-inch circle of metal slightly different in color from the rest of the door. It seemed perfectly flush with the metal around it. Just above the circle was a little dot of copper.
Both objects were matched in the jamb of the door—the copper spot by another precisely similar, the circle by a shallow, bowl-shaped indentation of equal size and perhaps a millimeter deep. No means of activating the lock, if it were one, were visible. Stevenson stared at the system for several minutes, Preble trying to see around the curve of his helmet.
“It’s crazy,” the chemist said at last. “If that circle marks a bolt, why isn’t it shaped to fit the hollow on the jamb? It couldn’t be moved forward a micron, the way it is. And the thing can’t be a magnetic lock—the hollow proves that, too. You’d want the poles to fit as snugly as possible, not to have the field weakened by an air gap. What is it?”
Preble blinked, and almost bared his head in reverence, but was stopped by his helmet. “You have it, friend,” he said gently. “It is a magnetic lock. I’d bet”—he glanced at the lung dial on his wrist—“my chance of living another hundred hours that’s the story. But it’s not based on magnetic attraction—it’s magnetostriction. A magnetic field will change the shape of a piece of metal—somewhat as a strong electric field does to a crystal. They must have developed alloys in which the effect is extreme. When the current is on, that ‘bolt’ of yours fits into the hollow in the jamb, without any complicated lever system to move it. This, apparently, is a cargo hold, and all the doors are probably locked by one master switch—perhaps on the control board, but more probably down here somewhere. So long as a current is flowing, the doors are locked. The current in any possible storage device must have been exhausted ages ago, even if these were left locked.”
“But what about the engine-room door?” asked Stevenson. “Could that have been of this type? It was locked, remember.” Preble thought for a moment.
“Could be. The removable block might have been a permanent magnet that opposed another when it was in one way, and reinforced it when it was reversed. Of course, it would be difficult to separate them once they were placed in the latter position; maybe the ship’s current was used to make that possible. Now that the current is off, it may be that there will be some difficulty in returning that block to its original position. Let’s go and see.” He led the way back along the corridor to the ramp.
* * *
Cray received the theory with mingled satisfaction and annoyance; he should, he felt, have seen it himself. He had already discovered that the triangular blocks had developed an attachment for their new positions, and had even considered magnetism in that connection; but the full story had escaped him. He had had other things to worry about, anyway.
The free-lance seekers had met the engineer at the entrance to the engine room. Now the three moved inside, stepping out onto a catwalk similar to that in the control room. This chamber, however, was illuminated only by the hand torches of the men; and it was amazing to see how well they lit up the whole place, reflecting again and again from polished metal surfaces.
When one had seen the tube arrangement from outside the ship, it was not difficult to identify most of the clustered machines. The tube breeches, with their heavy injectors and disintegrators, projected in a continuous ring around the walls and in a solid group from the forward bulkhead. Heavily insulated leads ran from the tubes to the supplementary cathode ejectors. It seemed evident that the ship had been driven and steered by reaction jets of heavy-metal ions, as were the vessels of human make. All the machines were encased in heavy shields, which suggested that their makers were not immune to nuclear radiation.
“Not a bad layout,” remarked Preble. “Found out whether they’ll run?”
Cray glared. “No!” he answered almost viciously. “Would you mind taking a look at their innards for us?”
Preble raised his eyebrows, and stepped across the twenty-foot space between the catwalk and the nearest tube breech. It was fully six feet across, though the bore was probably not more than thirty inches—the walls had to contain the windings for the field which kept the ion stream from actual contact with the metal. The rig which was presumably the injector-disintegrator unit was a three-foot bulge in the center, and the insulated feed tube led from it to a nearby fuel container. The fuel was probably either mercury or some other easily vaporized heavy metal, such as lead. All this seemed obvious and simple enough, and was similar in basic design to engines with which even Preble was familiar; but there was a slight departure from convention in that the entire assembly, from fuel line to the inner hull, appeared to be one seamless surface of metal. Preble examined it closely all over, and found no trace of a joint.
“I see what you mean,” he said at last, looking up. “Are they all the same?” Cray nodded.
“They seem to be. We haven’t been able to get into any one of them—even the tanks are tight. They look like decent, honest atomics, but we’ll never prove it by looking at the outside.”
“But how did they service them?” asked Stevenson. “Surely they didn’t weld the cases on and hope their machines were good enough to run without attention. That’s asking too much, even from a race that built a hull that could hold air as long as this must have.”
“How could I possibly know?” growled Cray. “Maybe they went outside and crawled in through the jets to service ’em—only I imagine it’s some trick seal like the door of this room. After all, that was common sense, if you look at it right. The fewer moving parts, the less wear. Can anyon
e think of a way in which this breech mechanism could be fastened on, with an invisible joint, working from the same sort of common sense?”
Why no one got the answer then will always remain a mystery; but the engineer was answered by nothing but half a dozen thought expressions more or less hidden in space helmets. He looked around hopefully for a moment, then shrugged his shoulders. “Looks like we’ll just have to puzzle around and hope for the best,” he concluded. “Jack and Don might as well go back to their own snooping—and for Heaven’s sake, if you get any more ideas, come a-runnin’.”
After glancing at Grant for confirmation of the suggestion, Preble and Stevenson left the engine room to continue their interrupted tour.
“I wonder if the upper section behind the control room is sealed,” remarked the chemist as they entered the darkness of the corridor. “I think we’ve covered the bow fairly well.” Preble nodded; and without further speech they passed through the control chamber, glancing at the board which had given Grant and McEachern such trouble, and found, as they expected, ramps leading up and down opening from the rear corridor just as one entered.
They stayed together this time, and climbed the starboard spiral. The door at the top opened easily, which was some relief; but the hallway beyond was a disappointment. It might have been any of the others already visited; and a glance into each of the rooms revealed nothing but bare metal gleaming in the flashlight beams, and dust-covered floors. The keel corridor was also open; but here was an indication that one, at least, of the rooms had been used for occupancy rather than cargo.
Stevenson looked into it first, since it was on the side of the corridor he had taken. He instantly called his companion, and Preble came to look at the object standing in the beam of the chemist’s light.
It was a seat, identical to the one in the control chamber—a mound of metal, with five deep grooves equally spaced around it. The tiny reflected images of the flashlights stared up from its convex surfaces like luminous eyes. None of the other furniture that had characterized the room in the central bow corridor was present; but the floor was not quite bare.
Opposite each of the five grooves in the seat, perhaps a foot out from it, a yard-long metal cable was neatly welded to the floor. A little farther out, and also equally spaced about the seat, were three more almost twice as long. The free end of each of the eight cables was cut off cleanly, as though by some extremely efficient instrument; the flat cut surfaces were almost mirror-smooth. Stevenson and Preble examined them carefully, and then looked at each other with thoughtful expressions. Both were beginning to get ideas. Neither was willing to divulge them.
There remained to explore only the stern engine room and the passage leading to it, together with the rooms along the latter. They had no tools with which to remove a specimen of one of the cables, so they carefully noted the door behind which the seat and its surroundings had been found, and climbed once more to the central deck. Before making their last find, they had begun to be bored with the rather monotonous search, particularly since they had no clear idea of what they were searching for; without it, they might have been tempted to ignore the rooms along the corridor and go straight to the engine room. Now, however, they investigated every chamber carefully; and their failure to find anything of interest was proportionally more disappointing.
And then they reached the engine-room door.
Flashlights swept once over the metal surface, picking out three disks with their inset triangular blocks, as the men had expected, but the coppery reflection from two of the blocks startled them into an instant motionlessness. Of the three seals, they realized, only one—the uppermost—was locked. It was as though whoever had last been in the room had left hastily—or was not a regular occupant of the ship.
Preble quickly reversed the remaining block, and unscrewed the three disks; then the two men leaned against the door and watched it swing slowly open. Both were unjustifiably excited; the state of the door had stimulated their imaginations, already working overtime on the material previously provided. For once, they were not disappointed.
The light revealed, besides the tanks, converters, and tube breeches which had been so obvious in the forward engine room, several open cabinets which had been mere bulges on the walls up forward. Tools and other bits of apparatus filled these and lay about on the floor. Light frameworks of metal, rather like small building scaffolds, enclosed two of the axial tube breeches; and more tools lay on these. It was the first scene they had encountered on the ship that suggested action and life rather than desertion and stagnation. Even the dust, present here as everywhere, could not eradicate the impression that the workers had dropped their tools for a brief rest, and would return shortly.
Preble went at once to the tubes upon which work had apparently been in progress. He was wondering, as he had been since first examining one, how they were opened for servicing. He had never taken seriously Cray’s remark that it might have been done from outside.
His eye caught the thing at once. The dome of metal that presumably contained the disintegrator and ionizing units had been disconnected from the fuel tank, as he had seen from across the room; but a closer look showed that it had been removed from the tube, as well, and replaced somewhat carelessly. It did not match the edges of its seat all around, now; it was displaced a little to one side, exposing a narrow crescent of flat metal on each of the two faces normally in complete contact. An idea of the position can be obtained by placing two pennies one on the other, and giving the upper one a slight sideward displacement.
The line of juncture of the two pieces was, therefore, visible all around. Unfortunately, the clamping device Preble expected to find was not visible anywhere. He got a grip—a very poor one, with his gloved hand—on the slightly projecting edge of the hemisphere, and tried to pull it free, without success; and it was that failure which gave him the right answer—the only possible way in which an airtight and pressure-tight seal could be fastened solidly, even with the parts out of alignment, with nonmagnetic alloys. It was a method that had been used on Earth, though not on this scale; and he was disgusted at his earlier failure to see it.
Magnetism, of course, could not be used so near the ion projectors, since it would interfere with the controlling fields; but there was another force, ever present and available—molecular attraction. The adjoining faces of the seal were plane, not merely flat. To speak of their accuracy in terms of the wave length of sodium light would be useless; a tenth-wave surface, representing hours of skilled human hand labor, would be jagged in comparison. Yet the relatively large area of these seals and the frequency with which the method appeared to have been used argued mass production, not painstaking polishing by hand.
But if the seal were actually wrung tight, another problem presented itself. How could the surfaces be separated, against a force sufficient to confine and direct the blast of the ion rockets? No marks on the breech suggested the application of prying tools—and what blade could be inserted into such a seal?
Stevenson came over to see what was keeping Preble so quiet, and listened while the latter explained his discovery and problems.
“We can have a look through these cabinets,” the chemist remarked finally. “This seems to fit Sorrell’s idea of a tool-requiring job. Just keep your eyes and mind open.”
The open mind seemed particularly indicated. The many articles lying in and about the cabinets were undoubtedly tools, but their uses were far from obvious. They differed from manmade tools in at least one vital aspect. Many of our tools are devices for forcing: hammers, wrenches, clamps, pliers, and the like. A really good machine job would need no such devices. The parts would fit, with just enough clearance to eliminate undesired friction—and no more.
That the builders of the ship were superb designers and machinists was already evident. What sort of tools they would need was not so obvious. Shaping devices, of course; there were planers, cutters, and grinders among the littered articles. All were portable, b
ut solidly built, and were easily recognized even by Preble and Stevenson. But what were the pairs of slender rods which clung together, obviously magnetized? What were the small, sealed-glass tubes; the long, grooved strips of metal and plastic; the featureless steel-blue spheres; the iridescent, oddly shaped plates of paper-thin metal? The amateur investigators could not even guess, and sent for professional help.
* * *
Cray and his assistants almost crooned with pleasure as they saw the untidy floor and cabinets; but an hour of careful examination and theorizing left them in a less pleasant mood. Cray conceded that the molecular attraction theory was most probably correct, but made no headway at all on the problem of breaking the seal. Nothing in the room seemed capable of insertion in the airtight joint.
“Why not try sliding them apart?” asked Stevenson. “If they’re as smooth as all that, there should be no difficulty.”
Cray picked up a piece of metal. “Why don’t you imagine a plane through this bar, and slide it apart along that?” he asked. “The crystals of the metal are practically as close together, and grip each other almost as tightly, in the other case. You’ll have to get something between them.”
The chemist, who should have known more physics, nodded. “But it’s more than the lubricant that keeps the parts of an engine apart,” he said.
“No, the parts of one of our machines are relatively far apart, so that molecular attraction is negligible,” answered the machinist. “But—I believe you have something there. A lubricant might do it; molecules might conceivably work their way between those surfaces. Has anybody noticed anything in this mess that might fill the bill?”
“Yes,” answered Preble promptly, “these glass tubes. They contain liquid, and have been fused shut—which is about the only way you could seal in a substance such as you would need.”
