Becky responded to his call, and they made a smoke-mark for future guidance, and started upon their quest. They wound this way and that, far down into the secret depths of the cave, made another mark, and branched off in search of novelties to tell the upper world about. In one place they found a spacious cavern, from whose ceiling depended a multitude of shining stalactites of the length and circumference of a man's leg; they walked all about it, wondering and admiring, and presently left it by one of the numerous passages that opened into it. This shortly brought them to a bewitching spring, whose basin was incrusted with a frostwork of glittering crystals; it was in the midst of a cavern whose walls were supported by many fantastic pillars which had been formed by the joining of great stalactites and stalagmites together, the result of the ceaseless water-drip of centuries. Under the roof vast knots of bats had packed themselves together, thousands in a bunch; the lights disturbed the creatures and they came flocking down by hundreds, squeaking and darting furiously at the candles. Tom knew their ways and the danger of this sort of conduct. He seized Becky's hand and hurried her into the first corridor that offered; and none too soon, for a bat struck Becky's light out with its wing while she was passing out of the cavern. The bats chased the children a good distance; but the fugitives plunged into every new passage that offered, and at last got rid of the perilous things. Tom found a subterranean lake, shortly, which stretched its dim length away until its shape was lost in the shadows. He wanted to explore its borders, but concluded that it would be best to sit down and rest awhile, first. Now, for the first time, the deep stillness of the place laid a clammy hand upon the spirits of the children. Becky said:

"Why, I didn't notice, but it seems ever so long since I heard any of the others."

"Come to think, Becky, we are away down below them--and I don't know how far away north, or south, or east, or whichever it is. We couldn't hear them here."

Becky grew apprehensive.

"I wonder how long we've been down here, Tom? We better start back."

"Yes, I reckon we better. P'raps we better."

"Can you find the way, Tom? It's all a mixed-up crookedness to me."

"I reckon I could find it--but then the bats. If they put our candles out it will be an awful fix. Let's try some other way, so as not to go through there."

"Well. But I hope we won't get lost. It would be so awful!" and the girl shuddered at the thought of the dreadful possibilities.

They started through a corridor, and traversed it in silence a long way, glancing at each new opening, to see if there was anything familiar about the look of it; but they were all strange. Every time Tom made an examination, Becky would watch his face for an encouraging sign, and he would say cheerily:

"Oh, it's all right. This ain't the one, but we'll come to it right away!"

But he felt less and less hopeful with each failure, and presently began to turn off into diverging avenues at sheer random, in desperate hope of finding the one that was wanted. He still said it was "all right," but there was such a leaden dread at his heart that the words had lost their ring and sounded just as if he had said, "All is lost!" Becky clung to his side in an anguish of fear, and tried hard to keep back the tears, but they would come. At last she said:

"Oh, Tom, never mind the bats, let's go back that way! We seem to get worse and worse off all the time."

"Listen!" said he.

Profound silence; silence so deep that even their breathings were conspicuous in the hush. Tom shouted. The call went echoing down the empty aisles and died out in the distance in a faint sound that resembled a ripple of mocking laughter.

"Oh, don't do it again, Tom, it is too horrid," said Becky.

"It is horrid, but I better, Becky; they might hear us, you know," and he shouted again.

The "might" was even a chillier horror than the ghostly laughter, it so confessed a perishing hope. The children stood still and listened; but there was no result. Tom turned upon the back track at once, and hurried his steps. It was but a little while before a certain indecision in his manner revealed another fearful fact to Becky--he could not find his way back!