For three days and nights priests relieved each other at intervals; but upon the morning of the fourth day Tarzan discovered that the corridor was empty, and once again he turned his attention actively to thoughts of escape.
It had so happened that at the time of Tarzan's capture his hunting knife had been hidden by the tail of the leopard skin that formed his loin cloth; and, in their excitement, the ignorant, half- human priests of Opar had overlooked it when they took his other weapons away from him. Doubly thankful was Tarzan for this good fortune, since, for sentimental reasons, he cherished the hunting knife of his long dead sire the knife that had started him upon the upward path to ascendancy over the beasts of the jungle that day, long gone, when, more by accident than intent, he had plunged it into the heart of Bolgani, the gorilla. But for more practical reasons it was, indeed, a gift from the gods, since it afforded him not only a weapon of defense, but an instrument wherewith he might seek to make good his escape.
Years before had Tarzan of the Apes escaped from the pits of Opar, and so he well knew the construction of their massive walls. Granite blocks of various sizes, hand hewn to fit with perfection, were laid in courses without mortar, the one wall that he had passed through having been fifteen feet in thickness. Fortune had favored him upon that occasion in that he had been placed in a cell which, unknown to the present inhabitants of Opar, had a secret entrance, the opening of which was closed by a single layer of loosely laid courses that the ape-man had been able to remove without great effort.
Naturally he sought for a similar condition in the cell in which he now found himself, but his search was not crowned with success. No single stone could be budged from its place, anchored as each was by the tremendous weight of the temple walls they supported; and so, perforce, he turned his attention toward the door.
He knew that there were few locks in Opar since the present degraded inhabitants of the city had not developed sufficient ingenuity either to repair old ones or construct new. Those locks that he had seen were ponderous affairs opened by huge keys and were, he guessed, of an antiquity that reached back to the days of Atlantis; but, for the most part, heavy bolts and bars secured such doors as might be fastened at all, and he guessed that it was such a crude contrivance that barred his way to freedom.
Groping his way to the door, he examined the small opening that let in air. It was about shoulder high and perhaps ten inches square and was equipped with four vertical iron bars half an inch square, set an inch and a half apart—too close to permit him to insert his hands between them, but this fact did not entirely discourage the ape-man. Perhaps there was another way.
His steel thewed fingers closed upon the center of one of the bars. With his left hand he clung to another, and bracing one knee high against the door he slowly flexed his right elbow. Rolling like plastic steel, the muscles of his forearm and his biceps swelled, until gradually the bar bent inward toward him. The ape-man smiled as he took a new grip upon the iron bar. Then he surged backward with all his weight and all the strength of that mighty arm, and the bar bent to a wide U as he wrenched it from its sockets. He tried to insert his arm through the new opening, but it still was too small. A moment later another bar was torn away, and now, his arm through the aperture to its full length, he groped for the bar or bolts that held him prisoner.
At the fullest extent to which he could reach his fingertips downward against the door, he just touched the top of the bar, which was a timber about three inches in thickness. Its other dimensions, however, he was unable to ascertain, or whether it would release by raising one end or must be drawn back through keepers. It was most tantalizing! To have freedom almost within one's grasp and yet to be denied it was maddening.
Withdrawing his arm from the aperture, he removed his hunting knife from his scabbard and, again reaching outward, pressed the point of the blade, into the wood of the bar. At first he tried lifting the bar by this means, but his knife point only pulled out of the wood. Next, he attempted to move the bar backward in a horizontal plane, and in this he was successful. Though the distance that he moved it in one effort was small, he was satisfied, for he knew that patience would win its reward. Never more than a quarter of an inch, sometimes only a sixteenth of an inch at a time, Tarzan slowly worked the bar backward. He worked methodically and carefully, never hurrying, never affected by nervous anxiety, although he never knew at what moment a savage warrior priest of Opar might make his rounds; and at last his efforts were rewarded, and the door swung upon its hinges.
Stepping quickly out, Tarzan shot the bar behind him and, knowing no other avenue of escape, turned back up the corridor along which his captors had conducted him to his prison cell. Faintly in the distance he discerned a lessening darkness, and toward this he moved upon silent feet. As the light increased slightly, he saw that the corridor was about ten feet wide and that at irregular intervals it was pierced by doors, all of which were closed and secured by bolts or bars.
A hundred yards from the cell in which he had been incarcerated he crossed a transverse corridor, and here he paused an instant to investigate with palpitating nostrils and keen eyes and ears. In neither direction could he discern any light, but faint sounds came to his ears indicating that life existed somewhere behind the doors along this corridor, and his nostrils were assailed by a medley of scents—the sweet aroma of incense, the odor of human bodies and the acrid scent of carnivores; but there was nothing there to attract his further investigation, so he continued on his way along the corridor toward the rapidly increasing light ahead.
He had advanced but a short distance when his keen ears detected the sound of approaching footsteps. Here was no place to risk discovery. Slowly he fell back toward the transverse corridor, seeking to take concealment there until the danger had passed; but it was already closer than he had imagined, and an instant later half a dozen priests of Opar turned into the corridor from one just ahead of him. They saw him instantly and halted, peering through the gloom.
"It is the ape-man," said one. "He has escaped," and with their knotted cudgels and their wicked knives they advanced upon him.
That they came slowly evidenced the respect in which they held his prowess, but still they came; and Tarzan fell back, for even he, armed only with a knife, was no match for six of these savage half- men with their heavy cudgels. As he retreated, a plan formed quickly in his alert mind, and when he reached the transverse corridor he backed slowly into it. Knowing that now that he was hidden from them they would come very slowly, fearing that he might be lying in wait for them, he turned and ran swiftly along the corridor. He passed several doors, not because he was looking for any door in particular, but because he knew that the more difficult it was for them to find him the greater his chances of eluding them; but at last he paused before one secured by a huge wooden bar. Quickly he raised it, opened the door and stepped within just as the leader of the priests came into view at the intersection of the corridor.