Nature took her full toll of his weary body, and it was nearly nine next morning before Dundas kicked off his bed clothes with a hearty exclamation of dismay at his laxness. He awoke keenly alive to the possibilities of the day before him, and after hurrying through his domestic routine he made his way to the shed with a handful of tools. He fixed his lamp so as to give the best possible light, and then, by means of careful sounding, he marked out with chalk the area that rang hollow beneath his hammer, and which he finally estimated was about a foot square.
Before long, by working on one spot, he had penetrated about an inch, when, to his delight, a small hole, no larger than a pin’s head, appeared. Once broken through, he found that the work of enlarging the opening became easier. The cement began to fly in larger fragments from the edge of the chisel. In about two hours he had enlarged the opening sufficiently to admit his hand, but in spite of his eagerness he refrained from a close examination of the interior. It was when lunch time arrived, and half the area that had been marked out was broken down, that he turned the light inwards only to meet with disappointment. One inch behind the cement was a metal plate that blocked his view. This, he found, was loose, but he could not remove it until he had cleared away the whole of the cement. If they had done nothing else, his difficulties had made him philosophic. He had come to recognise the fact that whatever the intelligence was that had created his discovery, that intelligence had so adjusted matters that the secret could not be lightly violated.
The result of his work next morning justified his surmise about the metal plate. He found that the recess was just ten inches square, but so accurate had been the fitting that while a chip of the cement remained round the edges it was impossible to remove it. Smoking contentedly he pegged away at the work, his thoughts all the while as busy as his hands. All the edges were clear, and at last he chipped the fragments that still held the corners until by careful coaxing he was enabled to work out the metal plate. As he did so it slipped through his fingers and fell clattering to his feet. Quickly Alan turned his light into the recess. It was not more than four inches deep, allowing for the inch of cement he had removed, but small as it was it held enough to call forth a quick exclamation of pleasure. Arranged in the form of a square at the back of it were four small, bright metal knobs, each one of which reflected back the rays of the acetylene lamp from brilliant points of light. Each knob was at the end of a stem protruding from the wall, and each stem sprang from the intersecting point of two deep grooves that formed a crosscut in the cement. “So,” said Alan softly, “this is the open sesame — now I think I’ll step right inside, or perhaps this is merely a — hell!” With the forefinger of his right hand he had touched one of the knobs. The next instant he was lying in the bottom of the shaft in a sickly odour of acetylene gas, with the extinguished lamp beneath him.
He pulled himself painfully together, ruefully rubbing the various bumps he had acquired during his somersault, and wondering whether his jarred system were entirely sound. “Well, I’ll be hanged if that wasn’t a dirty trick to play on the innocent investigator — electricity! And the father of sin himself only knows how many volts. No, my friends,” he went on, addressing the unknown builders, “you certainly did not mean that door to be opened by a fool.” He dragged himself to the surface and examined his lamp to find it intact and in good order. Then he turned, and looking into the darkness at his feet, asked in injured tones how many more surprises it held for him. He relighted the lamp, and returned to the doorway. The glittering knobs winked back at him as he turned the light on them. Fixing his lamp behind him so as to have both hands free, he sat down and regarded the recess sourly. “Now I wonder,” he said to himself presently, “did I get it all the first time, or is there more to follow? I wish to goodness I knew something about electricity.” Putting his fingers up gingerly, he touched the same knob again. Even prepared as he was, the shock he received brought forth an angry grunt of pain, and again he almost overbalanced himself. He rubbed his quivering arm savagely. “Knowledge may be strength,” he said angrily, “but it’s confoundedly painful to get in this locality. No, this is certainly no place for fools. However, we’ll see.” He roused himself, and scrambling to the surface betook himself to the house. He ran his eye over his bookshelves, and pulled down a volume, and for a quarter of an hour he buried his nose in its pages. Finally he banged the book with his open hand. “Might have thought of it before if my head had not been wool-gathering,” he said aloud, then with his hands in his pockets he leaned back in his chair and stared through the window, whistling softly. Suddenly he sprang up. “The very thing!” He went to his bedroom and returned with an old raincoat, which he flung on the table. Spreading the garment before him, he took his pocket-knife and cut a 3 inch strip from the lower hem, and then carefully examined the material. “Yes,” he repeated, “the very thing,” and proceeded to cut from the strip four pieces about 3 inches square, and with these and some twine he hurried back to the shaft.
“Now, my friends,” he said, as he seated himself on his box before the recess. “We’ll see who knows most.” Holding a piece of the cloth-cased rubber carefully in his fingers, he pressed it to the knob with, as he expected, entire success, for his simple non-conductor answered his purpose. Then he folded the cloth carefully about the shank, and fastened it in place with twine, working gingerly, so as to keep his hands from coming into contact with the other danger points. Then he treated the other three in the same manner, and found he could handle them all without fear.
So far so good. Now what were the knobs for? How were they to be operated? A few tentative presses and twists soon found an answer. Each one could move in four directions, for deep in the cement the shanks worked on a pivot that allowed the knobs to follow the lines of the crossed grooves, up or down, right or left, and realising this, Alan realised, too, that he was face to face with a problem that might baffle him for an indefinite time. That the door could be operated by the knobs he felt certain, but he felt more certain that he was faced by a cunningly contrived combination lock that would test his wits to the uttermost before he won success.
There were in all five positions, counting the upright, in which each knob might be placed, and there were four knobs. “Now bless my soul,” Dundas murmured, “I wonder how many thousand variations the dashed things are capable of, and must I go on fiddling with them until I’m grey-headed? Reminds me of how many places nine men in a boat can be put in. Only this is worse.”
With a silent prayer for patience he began to work, moving the levers to and fro, trying them systematically in rotation, combination after combination, till his arms ached from being held in the one position, and his fingers almost refused to do his bidding. Then in the end he sat back and filled his pipe. So busy had he been that time had passed unnoticed, and it was only the clamouring of an angry stomach that directed his attention to the hour, and he found to his surprise that night had fallen while he worked. Another night, and he was still outside the longed-for goal! It was no use going on, he told himself. For all he knew, unless he stumbled on the right combination by accident, it might take him weeks or months to exhaust all possible variations of the levers. Stiff and tired, he dragged himself to the surface, and then to the homestead, disgusted with his failure.
Alan set out for the shed next morning in a cheerful mood, and with the determination to stick to his task, in spite of failure. He had re-charged his lamp, and he set to work, whistling light-heartedly. Following up his first idea, he commenced by numbering the levers from one to four, and then he moved them alternatively in numerical rotation, thus avoiding a repetition of variations. It was a tiresome task, but he relieved the monotony with an occasional pause for a smoke, and to stretch his cramped limbs. As time passed his movements became mechanical. He leaned forward with his face close to the recess, and his elbows against the wall to relieve his tired body, for he found his occupation more trying than the hard manual work that had preceded it. He was thinking vaguely that it was about time for lunch, when he suddenly started up. He had heard nothing move, but some subtle sense told him of a change. He turned his head slightly, and an involuntary cry broke from his lips. The mighty door had disappeared, and he was staring into the blackness beyond where it had been.
Erle Cox, Out of the Silence, Melbourne: Robertson and Mullens, 1947 (first published 1925), pages 64-69