CHAPTER XXV.
A STRANGE ADVENTURE.
Early the next day the explorers, boys and adults, resumed theirinvestigation of the Lost City. The professor estimated that it wouldtake some time before they had completed their work and collectedrelics, records and films of the various features of absorbingscientific interest to be found there.
Joe and Nat struck out in one direction, while the Professor, Ding-dongand Mr. Tubbs assumed another line of investigation. The path taken bythe two boys led them down one of the crumbling streets to the lakefront of the Lost City. On the way they entered several of the housesand collected some small relics and Joe, who had some talent that way,busied himself in making rough sketches of the buildings they examined.
At last, thoroughly tired out, the two lads sat themselves down on araised pile of carefully fitted stones in the courtyard of a splendidwhite building with a pyramid-like cupola. They had brought somesandwiches and a flask of water with them and made a light meal whilethey rested.
“Seems like a sort of sacrilege to be eating corned beef sandwiches inwhat may have been a temple,” said Nat as he ate.
Joe laughed.
“From what we know of the folks that used to live here they used tomake corned beef out of anyone they didn’t like, so don’t worry aboutthat end of it, old fellow.”
“That’s so,” agreed Nat. “I wonder, for instance, if this businesswe’re sitting on at this moment isn’t an old altar of some kind. Looksas if it might have been.”
“It does that,” agreed Joe, “and see here, Nat, here’s a metal ringright here in this slab of stone. I wonder if they used to tie theirpoor victims to it?”
He indicated a big ring of dull, greenish metal which they had notnoticed before. It was countersunk in one of the slabs of stone thatformed the top of the altar.
Nat examined it.
“I guess more likely it was used to raise this stone,” he said. “Maybethe altar is hollow inside and contains relics of some sort.”
“Cracky! I’d like to raise it,” declared Joe; but, although he tuggedand pulled till his ruddy face was redder than usual, Joe could make noimpression on the stone.
“Let me try,” suggested Nat.
With what idea, he could not exactly say, the boy gave the ring agentle twisting motion instead of tugging at it. Then an astonishingthing happened. The entire top of the altar tipped downward and theboys were shot, scrambling and struggling, into the interior of thealtar, if such it had been. Before they knew just what had occurredthey found themselves in total darkness, for, having tipped them off,the stone had swung into place again.
A thrill of fear crept icily through Nat’s veins as he realized thatthey were prisoners. But he put all the heart he could into his replywhen Joe in a frightened voice gasped out:
“What on earth happened, Nat?”
“Why, just this,” was the reply. “That altar top was counterbalanced.Our weight was on one end of it. In some way, when I twisted that ring,a spring or catch must have been loosened and—and—we’re in the interiorof the altar.”
“Can we get out again, do you think?”
“That’s just what we’ve got to find out, and quickly, too, Joe,” wasthe response. “Got any matches?”
“Yes; luckily I brought some. I’ve got a pocket lantern here, too, witha candle in it. Shall I light up?”
“Yes, do so as soon as you can,” rejoined Nat.
The next minute the interior of the altar was illumined by a yellowlight. But so perfectly had the swinging top of the altar been fittedthat not a crevice appeared and as for any lever or handle by which itmight have been opened, none was revealed by the light.
But it was some minutes before the boys found out this fact. When theydid, however, it came with a sense of stunning bitterness. If theycould not find a means of egress from the altar, they were, in allhuman probability, doomed to die in that gloomy prison.
Although they both realized their situation, neither lad voiced hisfears. There still remained one end of the altar to be examined, andNat lost no time in proceeding to investigate the hitherto neglectedportion of their prison. But its masonry appeared to be as solidlyconstructed as was the case in every other part of the altar. Nat,almost in despair, was turning away when Joe, who had been at his side,gave a sudden cry.
“Nat! Nat! There’s a stone loose here. I can move it with my foot. WhenI press down on it—Great-jumping-horned-toads!”
Joe’s exclamation was caused by the fact that as he pressed down on theloose stone a small door opened out before them in the end of thealtar. It was impossible to say, however, whither it led, as beyond laytotal darkness.
“What do you say, shall we try it?” asked Joe in a rather tremulousvoice, for the darkness looked singularly mysterious and forbidding.
“We’ve _got_ to try it,” said Nat gloomily. “It’s our only alternative,unless we want to stay here and starve to death.”
Joe had to agree that this was a true statement of the facts of thecase, and not without quickened pulses the two lads made the plungeinto the darkness beyond the door. The portal was square and so lowthat they had to bend to get through it. The rays of Joe’scandle-lantern showed the two youths that they were in a low-roofedpassage, or tunnel, just wide enough for them to proceed in single file.
“You go first,” said Joe in a rather quivery tone, which showed betterthan anything else that the adventure was having its effect upon him,the usually unperturbed.
“All right, give me the lantern.”
“I wonder where this passage can lead to?”
“Haven’t the least idea. I think we are going south, but I’m not sure.”
“I’m all twisted up, too. I wish we’d left that old ring alone.”
“Maybe I don’t, too. If we ever get out of this place, I’ll leave allsuch devices severely to themselves in future.”
“Have you any idea of the purpose of this passage?”
“Not I. Maybe it was used as a means of escape. In that case——”
“In that case we will get out to daylight again,” Joe concluded.
“On the other hand, it may have been designed as a means of executingtheir criminals or enemies. I’ve heard of such things.”
Joe fairly shuddered.
“Oh, talk of something pleasant,” he said, with a groan.
No more was said for a time. The circumstances didn’t make the boysfeel much inclined for conversation.
All at once they emerged into a vaulted chamber, seemingly cut out ofthe living rock. At the top of its arched roof was set a huge crystal,very like the one they had seen in the “telescope tower,” only muchlarger. Through this lens light was streaming into the place, the wallsof which were painted and carved with all manner of strange-lookinginscriptions and designs. Nat was so intent on gazing at these that hedid not look as carefully where he was going as he had in his progressdown the passage.
Suddenly his feet slipped from under him and he found himself fallingdownward. Joe uttered a cry as he saw his comrade vanish. He leapedforward, checking himself just in time to avoid sharing Nat’s plight.He found himself on the brink of a sort of well about ten feet deep. Atthe bottom of this was Nat. Joe uttered a cry of relief as Nat hailedhim and assured him that, by a miracle, he was not hurt.
“But how are you going to get out of there?” demanded Joe the nextinstant.
How, indeed? The question certainly was a poser. The walls of the wellwere as smooth as glass almost and Joe noticed a peculiar feature. Fromits “curb” radiated long lines extending over the floor of the rockychamber. These lines were cut in the rock and reminded Joe of lines hehad seen cut on a sun dial.
But he gave little thought to this at the moment. His mind was centeredon finding a means to get Nat out of his predicament. But, though hethought and thought, no solution of the problem occurred to him.
Joe was still wrapped in thought at the ed
ge of the well when he felt asudden blast of fearful heat on his back. He looked hastily round. Hisfirst thought was that some hidden fire must suddenly have burst intolife behind him.
But, no, what he had felt had been the rays of the sun pouring throughthe crystal at the top of the cavern and striking down withtremendously magnified force upon him.
“Phew! That felt like an oven!” exclaimed Joe, moving away.
It was a moment later that he observed something that filled him with avague sense of alarm, which swiftly crystallized into a sharp, lividpang of fear.
The sun was now striking down into the well. Like a thunderbolt thepurpose of the pit and the reason of the crystal lens burst upon Joe.
The ancient dwellers of the Lost City had been Sun Worshippers. Thischamber was a sacrificial one and the priests of the vanished race hadoffered up their victims’ lives by literally dedicating them to the Sungods. As this alarming truth broke upon Joe a faint cry came from Nat,down in the pit.
“Joe, for gracious sake, do something to get me out of here! The sun isstriking down into the pit. It is fearfully hot. If you don’t get meout soon I’ll be baked alive.”
Poor Joe cast his eyes about him despairingly. The sun was streamingthrough the lens at an angle now. What would happen when its directrays poured down into the narrow well he could not bear to think.