almost immediately thereafter I came upon a small door so cunningly inlaid in the shaft's base that it might have passed unnoticed by a less keen or careful observer.13
There was the door that would lead me within the prison, but where was the means to open it? No button or lock were visible. Again and again I went carefully over every square inch of its surface, but the most that I could find was a tiny pinhole a little above and to the right of the door's center--a pinhole that seemed only an accident of manufacture or an imperfection of material.
Into this minute aperture I attempted to peer, but whether it was but a fraction of an inch deep or passed completely through the door I could not tell--at least no light showed beyond it. I put my ear to it next and listened, but again my efforts brought negligible results.
During these experiments Woola had been standing at my side gazing intently at the door, and as my glance fell upon him it occurred to me to test the correctness of my hypothesis, that this portal had been the means of ingress to the temple used by Thurid, the
black dator, and Matai Shang, Father of Therns.
Turning away abruptly, I called to him to follow me. For a moment he hesitated, and then leaped after me, whining and tugging at my harness to draw me back. I walked on, however, some distance from the door before I let him have his way, that I might see precisely what he would do. Then I permitted him to lead me wherever he would.
Straight back to that baffling portal he dragged me, again taking up his position facing the blank stone, gazing straight at its shining surface. For an hour I worked to solve the mystery of the combination that would open the way before me.
Carefully I recalled every circumstance of my pursuit of Thurid, and my conclusion was identical with my original belief--that Thurid had come this way without other assistance than his own knowledge and passed through the door that barred my progress, unaided from within. But how had he accomplished it?
I recalled the incident of the Chamber of Mystery in the Golden Cliffs that time I had freed Thuvia of Ptarth from the dungeon
of the therns, and she had taken a slender, needle-like key from the keyring of her dead jailer to open the door leading back into the Chamber of Mystery where Tars Tarkas fought for his life with the great banths. Such a tiny keyhole as now defied me had opened the way to the intricate lock in that other door.
Hastily I dumped the contents of my pocket-pouch upon the ground before me. Could I but find a slender bit of steel I might yet fashion a key that would give me ingress to the temple prison.
As I examined the heterogeneous collection of odds and ends that is always to be found in the pocket-pouch of a Martian warrior my hand fell upon the emblazoned radium flash torch of the black dator.
As I was about to lay the thing aside as of no value in my present predicament my eyes chanced upon a few strange characters roughly and freshly scratched upon the soft gold of the case.
Casual curiosity prompted me to decipher them, but what I read carried no immediate meaning to my mind. There were three sets of characters, one below another:
3 |--| 50 T
1 |--| 1 X
9 |--| 25 T
For only an instant my curiosity was piqued, and then I replaced the torch in my pocket-pouch, but my fingers had not unclasped from it when there rushed to my memory the recollection of the conversation between Lakor and his companion when the lesser thern had quoted the words of Thurid and scoffed at them: "And what think you of the ridiculous matter of the light? Let the light shine with the intensity of three radium units for fifty tals"--ah, there was the first line of characters upon the torch's metal
case--3--50 T; "and for one xat let it shine with the intensity of one radium unit"--there was the second line; "and then for twenty-five tals with nine units."
The formula was complete; but--what did it mean?
I thought I knew, and, seizing a powerful magnifying glass from the litter of my pocket-pouch, I applied myself to a careful examination of the marble immediately about the pinhole in the door. I could have cried aloud in exultation when my scrutiny disclosed the almost invisible incrustation of particles of carbonized electrons which are thrown off by these Martian torches.
14
It was evident that for countless ages radium torches had been applied to this pinhole, and for what purpose there could be but a single answer--the mechanism of the lock was actuated by light rays; and I, John Carter, Prince of Helium, held the combination in my hand--scratched by the hand of my enemy upon his own torch case.
In a cylindrical bracelet of gold about my wrist was my Barsoomian chronometer--a delicate instrument that records the tals and xats and zodes of Martian time, presenting them to view beneath a strong crystal much after the manner of an earthly odometer.
Timing my operations carefully, I held the torch to the small aperture in the door, regulating the intensity of the light by means of the thumb-lever upon the side of the case.
For fifty tals I let three units of light shine full in the pinhole, then one unit for one xat, and for twenty-five tals nine units. Those
last twenty-five tals were the longest twenty-five seconds of my life. Would the lock click at the end of those seemingly interminable intervals of time?
Twenty-three! Twenty-four! Twenty-five!
I shut off the light with a snap. For seven tals I waited--there had been no appreciable effect upon the lock's mechanism. Could it be that my theory was entirely wrong?
Hold! Had the nervous strain resulted in a hallucination, or did the door really move? Slowly the solid stone sank noiselessly back into the wall--there was no hallucination here.
Back and back it slid for ten feet until it had disclosed at its right a narrow doorway leading into a dark and narrow corridor that paralleled the outer wall. Scarcely was the entrance uncovered than Woola and I had leaped through--then the door slipped quietly back into place.
Down the corridor at some distance I saw the faint reflection of a light, and toward this we made our way. At the point where the light shone was a sharp turn, and a little distance beyond this a brilliantly lighted chamber.
Here we discovered a spiral stairway leading up from the center of the circular room.
Immediately I knew that we had reached the center of the base of the Temple of the Sun--the spiral runway led upward past the inner walls of the prison cells. Somewhere above me was Dejah Thoris, unless Thurid and Matai Shang had already succeeded in stealing her.
We had scarcely started up the runway when Woola suddenly displayed the wildest excitement. He leaped back and forth, snapping
at my legs and harness, until I thought that he was mad, and finally when I pushed him from me and started once more to ascend he grasped my sword arm between his jaws and dragged me back.
No amount of scolding or cuffing would suffice to make him release me, and I was entirely at the mercy of his brute strength unless I cared to use my dagger upon him with my left hand; but, mad or no, I had not the heart to run the sharp blade into that faithful body.
Down into the chamber he dragged me, and across it to the side opposite that at which we had entered. Here was another doorway leading into a corridor which ran directly down a steep incline. Without a moment's hesitation Woola
