"I must see how deep it is first," was the reply, and the Norwegian jumped out and walked ahead with a long and slender pole he had brought along. Of a sudden he sank up to his waist. Then he stuck his pole down ahead of him. The snow was all of seven feet deep. He shook his head vigorously.

"We can't drive through there," said Dave. "Now what's to be done?"

Roger and Granbury Lapham stared around helplessly. The driver came back and began an inspection of the ground to the left. Here was another ridge. He said they might try skirting that, since there seemed nothing else to do.

"All right, anything so long as we get to Bojowak!" cried Dave.

The sleigh was turned partly around and the horses tugged and labored bravely to get through the snow on the new route. They went up a small rise of ground and then along a ridge that did not appear to be more than two yards wide. At one point there was a sharp decline on the left.

"We'll have to be careful here!" cried the Englishman to the driver.

"Otherwise we may all take a tumble."

He had hardly spoken when a sleigh ran up on a rock on one side and plunged into a hollow on the other. In a twinkling the turnout was upset. Dave felt himself pitched out and rolled over and over before he could stop himself. Then he went down and down, he knew not whither. His hand touched that of Roger, and instinctively the two chums clung to each other. The snow filled their eyes, ears, and noses, and almost smothered them. They saw a little light, and then suddenly all became pitch-dark around them.

For several seconds after they fell neither spoke, for each was busy collecting his scattered senses. They were side by side on their backs and the snow was still all around them. Dave put out an arm, felt something of an opening, and crawled into it.

"Roger, are you all right?"

"I--I guess so!" came in a spluttering voice. "But I must have rolled ov--er a hun--hundred times!"

"So did I. We came down on the lightning express, didn't we?"

"Where are we, and where is the sleigh?"

"Don't ask me. We're at the bottom of some place. Come here, there is more room to breathe."

The senator's son followed Dave into the opening the latter had found.

All was so dark here they could not see a thing. They stood close together, fearing to take another step.

"h.e.l.lo! h.e.l.lo!" yelled Dave, when he had his breath back, and Roger quickly joined in the cry. To their consternation there was no answer.

"Most likely the others went down, too," said Dave.

"Then they ought to be near here."

"Unless they slipped clear down to the bottom of the mountain. If they did that I guess it's good-bye to them."

"Oh, do you think they've been killed, Dave?"

"I don't know what to think. Let us call again."

They did so, a dozen times or more. But no answer came back. All around them it was as silent as a tomb.

While procuring their outfit Dave had invested in a pocket lantern, and this he now brought forth and lit. By the tiny rays he made out that they had tumbled into a hollow between several large rocks, over which the snow and ice hung thickly. A big bank of snow was in front of them and behind was a black-looking s.p.a.ce of uncertain depth.

"Roger, I must confess, I don't like the look of things."

"Don't like the look of things? Well, I guess not, Dave! How are we ever to get out?"

"I don't know."

"But we've got to get out somehow," went on the senator's son, desperately.

"We can't stay here forever."

"Not unless this place becomes our tomb."

"You are cheerful, to say the least," answered Roger, with a shiver.

"I don't intend the place shall be my tomb," went on Dave, st.u.r.dily. "I am going to get out somehow. Let us do a little exploring."

"What! go into that black hole behind us? Why, we may fall into a bottomless pit!"

"Not if we are careful."

"I don't want to take any more chances--I've taken enough."

Dave held the light low so that he could see where he was going and walked into the opening behind him for a couple of rods. Roger followed very gingerly, for he did not want to be left behind. The opening proved to be a cave in the mountain side and the roof and flooring were of almost solid rock. Walking was very rough, and they could not tell how far the cave extended or in what direction.

"I am going to call again," said Roger, and going back to the mouth of the cave they set up as strong a cry as before. At first they fancied somebody answered them, but then all became silent.

"Nothing doing," murmured the senator's son, and his face took on a look of deep anxiety. "Dave----" He stopped short.

"What?"

"Nothing, only--do you really think the others were killed?"

"Let us hope not," was Dave's grave reply.

CHAPTER XXIII

LEFT IN THE DARK

The thought that their two companions might possibly have been killed by the toppling over of the sleigh filled Dave and Roger with fresh horror, and for several minutes neither of the youths spoke. They listened for some sound, but none came. Then Roger heaved a deep sigh.

"Perhaps we had better try to climb out," he suggested, timidly.

"I've thought of that, Roger. But what if we slip when we get out? Why, the bottom of the valley is quarter of a mile further down. I don't want such a tumble, on top of the one we have already experienced."

"If we ever get out we'll have plenty of news to send home," was the senator's son's comment.

"True; but let us get out before we think of sending news."

They talked the matter over, and at length concluded to do a little more exploring of the cave. Dave turned up the pocket lantern as high as possible, and as he did this Roger took from his pocket a short, strong cord. "I thought this might come in useful, for tying up our supplies,"

explained the senator's son, "so I brought it from the last house we stopped at. Tie one end around your waist, Dave, and I will hold fast to the other end. Then I'll walk behind you, and if you go into a hole----"