He probably, in fact, would not have paid much attention. He knew, of course, that the sciences of physics and chemistry are important; but he thought of them in connection with great laboratories and factories. The idea that knowledge of either could be of immediate use to anyone not a chemist or physicist would have been fantastic to him. While his current plans for escape were based largely on chemistry, the connection did not occur to him. The only link between those plans and Mayhew's words or actions gave the spy some grim amusement; it was the fact that he did not smoke.
The cell, when he finally reached it, was perfectly satisfactory; there were no peepholes which could serve as shotholes, no way in which the door could be unsealed quickly — as Mayhew had said, not even a ventilator. Once he was in, Hart would not be interrupted without plenty of notice. Since the place was a storeroom, there was no reason to expect even a scanner, though, he told himself, there was no reason to assume there was none, either. He simply disregarded that possibility, and went to work the moment he heard the torch start to seal his door.
His first idea did not get far. He spent half an hour trying to make Mayhew's lighter work, without noticeable success. Each spin of the “flint” brought a satisfactory shower of sparks, and about every fourth or fifth try produced a faint “pop” and a flash of blue fire; but he was completely unable to make a flame last. He closed the cover at last, and for the first time made an honest effort to think. The situation had got beyond the scope of his training.
He dismissed almost at once the matter of the rocket fuel that had not been ignited by his bomb. Evidently the Westerners stored it with some inhibiting chemical, probably as a precaution more against accident than sabotage. Such a chemical would have to be easily removable, but he had no means of knowing the method, and that line of attack would have to be abandoned.
But why wouldn't the lighter fuel burn? The more he thought the matter out, the more Hart felt that Mayhew must have doctored it deliberately, as a gesture of contempt. Such an act he could easily understand; and the thought of it roused again the wolfish hate that was such a prominent part of his personality. He would show that smart Westerner! There was certainly some way!
Powerful hands, and a fingernail deliberately hardened long since to act as a passable screw-driver blade, had the lighter disassembled in the space of a few minutes. The parts were disappointingly small in number and variety; but Hart considered each at length.
The fuel, already evaporating as it was, appeared useless — he was no chemist, and had satisfied himself the stuff was incombustible. The case was of magnalium, apparently; and might be useful as a heat source if it could be lighted; its use in a cigarette lighter did not encourage pursuit of that thought. The wick might be combustible, if thoroughly dried. The flint and wheel mechanism was promising — at least one part would be hard enough to cut or wear most metals, and the spring might be decidedly useful.
Elsewhere in the room there was very little. The light was a gas tube, and, since the chamber had no opening whatever, would probably be most useful as a light. The alga tank, of course, had a minute motor and pump which forced air through its liquid, and an ingenious valve and trap system which recovered the air even in the present weightless situation; but Hart, considering the small size of the room, decided that any attempt to dismantle his only source of fresh air would have to be very much of a last resort.
After much thought, and with a grimace of distaste, he took the tiny striker of the lighter and began slowly to abrade a circular area around the latch of the door, using the inside handle for anchorage.
He did not, of course, have any expectation of final escape; he was not in the least worried about his chances of recovering his spacesuit. He expected only to get out of the cell and complete his mission; and if he succeeded, no possible armor would do him any good.
As it happened, there was a scanner in his compartment; but Mayhew had long since grown tired of watching the spy try to ignite the lighter fuel, and had turned his attention elsewhere, so that Hart's actions were unobserved for some time. The door metal was thin and not particularly hard; and he was able without interference and with no worse trouble than severe finger cramp to work out a hole large enough to show him another obstacle — instead of welding the door frame itself, his captors had placed a rectangular steel bar across the portal and fastened it at points well to each side of the frame, out of the prisoner's reach. Hart stopped scraping as soon as he realized the extent of this barrier, and gave his mind to the new situation.
He might, conceivably, work a large enough hole through the door to pass his body without actually opening the portal; but his fingers were already stiff and cramped from the use made of the tiny striker, and it was beyond reason to expect that he would be left alone long enough to accomplish any such feat. Presumably they intended to feed him occasionally.
There was another reason for haste, as well, though he was forgetting it as his nose became accustomed to the taint in the air. The fluid, which he had permitted to escape while disassembling the lighter, was evaporating with fair speed, as it was far more volatile than the rocket fuel; and it was diffusing through the air of the little room. The alga tank removed only carbon dioxide, so that the air of the cell was acquiring an ever-greater concentration of hydrocarbon molecules. Prolonged breathing of such vapors is far from healthy, as Hart well knew; and escape from the room was literally the only way to avoid breathing the stuff.
What would eliminate a metal door — quickly? Brute force? He hadn't enough of it. Chemicals? He had none. Heat? The thought was intriguing and discouraging at the same time, after his recent experience with heat sources. Still, even if liquid fuels would not burn perhaps other things would: there was the wicking from the lighter; a little floating cloud of metal particles around the scene of his work on the magnesium door; and the striking mechanism of the lighter.
He plucked the wicking out of the air where it had been floating, and began to unravel it — without fuel, as he realized, it would need every advantage in catching the sparks of the striker.
Then he wadded as much of the metallic dust as he could collect — which was not too much — into the wick, concentrating it heavily at one end and letting it thin out toward the more completely raveled part.
Then he inspected the edges of the hole he had ground in the door, and with the striker roughened them even more on one side, so that a few more shavings of metal projected. To these he pressed the fuse, wedging it between the door and the steel bar just outside the hole, with the “lighting” end projecting into the room. He inspected the work carefully, nodded in satisfaction, and began to reassemble the striker mechanism.
He did not, of course, expect that the steel bar would be melted or seriously weakened by an ounce or so of magnesium, but he did hope that the thin metal of the door itself would ignite.
Hart had the spark mechanism almost ready when his attention was distracted abruptly. Since the hole had been made, a very gentle current of air had been set up in the cell by the corridor ventilators beyond — a current in the nature of an eddy which tended to carry loose objects quite close to the hole. One of the loose objects in the room was a sphere comprised of the remaining lighter fluid, which had not yet evaporated. When Hart noticed the shimmering globe, it was scarcely a foot from his fuse, and drifting steadily nearer.