"My parents intend to stay in the south of France until spring," he replied. "My mother's health is poor. My father took her abroad to avoid cold weather."

"And you were left at college in New York," added Bogle, "in care of a lawyer, who acts as a sort of guardian. What brought you to Maine at this time of year?"

"I won't answer that," replied Brick, sullenly.

Bogle's eyes flashed. He made a threatening move forward. But a glance from Raikes checked him.

"If the answer was of any importance, I'd soon find a way to open your lips," he said, coolly. "Now sit down at that table and take the pen.

You must write two letters--one to your father, the other to this lawyer, Frederick Glendale, whose address you know. I will dictate them.

Do you understand?"

A light broke suddenly on Brick's bewildered mind. He saw now why he had been brought to this lonely place. His blood fairly boiled with indignation. He faced Bogle with flashing eyes.

"You may keep me here for a lifetime," he cried, angrily, "but I won't write a line."

CHAPTER XXI.

PLUNGED UNDER GROUND.

For two reasons Jerry and Hamp stayed but a short time at their temporary camp by the Mallowgash.

In the first place, Hamp quickly recovered from the chilling effects of his bath, and refused to be considered an invalid any longer. In the second place, both lads felt a growing uneasiness concerning Brick. They had no tangible suspicions or fears. They were merely anxious to overtake him, since they were, in a measure, responsible for his safety.

Accordingly, in a little more than an hour after the parting, they were ready to start. They crossed the Mallowgash at the frozen spot, and easily picked up the trail. The two heavy sleds delayed them somewhat.

On the whole, they did not travel quite so rapidly as the other party.

As time slipped by, their uneasiness grew upon them. They had expected, ere this, to meet Brick coming back. They were alarmed, too, by the threatening aspect of the weather.

Finally they reached the clearing by the stream. Here the short trail of blood gave them a terrible fright. Their looks meant what their lips were afraid to utter--the dread word "murder."

Then Jerry laughed.

"This is nonsense," he said. "It's nothing to be scared about, Hamp.

One of the party fell on the snow and sc.r.a.ped his nose. Look! here's where the crust is dented in."

"That's so," replied Hamp, in a relieved tone. "Cracky! I was scared for a minute."

"So was I," admitted Jerry. "They must be having a long, hard chase.

Still, they can't be much farther ahead."

"Let's walk faster," urged Hamp. "It's going to snow soon."

They turned to the right, barely glancing at the ledge of rocks and the brawling stream. They left the clearing and plunged into the scrub and timber in the direction of the lake.

They were moving too rapidly to notice that the imprint of but one pair of snowshoes was ahead of them. As they neared the lake, they struck a pitch of rising ground.

The boys dropped into single file. Hamp preceded, and Jerry followed with both sleds.

"I can see a bit of the lake through the trees," said Hamp. "It's not more than half a mile away. We ought to overtake the party between here and the sh.o.r.e."

Just then he struck a slippery pitch of rock and snow, and began to feel his way very cautiously. Six feet below was a fringe of bushes that shut off further view.

Meanwhile Jerry had fallen a little behind. He suddenly observed how slim and indistinct was the trail. He paused at once, and the sleds backed up against his ankles.

He bent over and keenly scrutinized the impressions on the snow.

"Hold on, Hamp," he cried. "Something wrong here. I see the marks of your snowshoes and of another pair. By cracky! we've blundered. There's been only one man ahead of us."

"How can that be?" exclaimed Hamp. "We didn't see any marks branching off."

He was startled by his companion's a.s.sertion. He tried to stop, but, unluckily, one foot slipped. He came forcibly down on the snow-crust in a sitting posture.

With a yell of dismay he shot down the slope and plunged through the fringe of bushes. A brief glimpse showed what was below--a circular depression of glistening snow s.c.r.e.w.i.n.g downward like a funnel, until it ended in a jagged black hole of extreme narrowness. The same glimpse made clear to Hamp that some one had created the depression by breaking through the crust of snow and gliding into an underlying cavity of unknown depth. For a fraction of a second Hamp stuck on the brink. He clutched vainly at air and snow. Then he shot down the abyss, feet first, and vanished through the black fissure at the bottom!

Jerry heard his companion's horrified cries. He knew that some catastrophe must have happened. He forgot all about his recent discovery, and plunged recklessly forward. The natural result was that the sleds banged him violently from the rear. Then came a dizzy drop through s.p.a.ce, and a collision with something soft, that yelled l.u.s.tily in Hamp's familiar tones.

"I--I couldn't help it," grasped Jerry, as he rolled to one side.

A second later it was his turn to sing out. A rifle, a haunch of venison, and half-a-dozen tin dishes pelted him in quick succession on the head and shoulders. He looked up with blinking eyes. Then he understood what the avalanche meant.

Ten feet overhead was the gap through which he had fallen. Both sleds had stuck there, and blocked it so completely that only a slim crevice of light was visible. The straps on one of the sleds had broken, allowing part of the contents to fall through.

Jerry held his breath for an instant, expecting another avalanche. When nothing more fell, he recovered his presence of mind.

"That you, Hamp?" he whispered. "Are you hurt?"

"I don't think so. I fell on a pile of snow."

"Neither am I," declared Jerry. "It was a lucky escape for both of us. I haven't got a bruise."

"No wonder," replied Hamp, in an injured tone. "You landed right on top of me. I'm just getting my wind back."

"I'm awfully sorry," said Jerry, "but I couldn't help it."

"Oh, that's all right. Only if I had known you were coming, I would have crawled out of the way. Where are we, anyhow?"

"That's what I want to know," Jerry replied. "It must be a cavern, Hamp.

The entrance was on top, and it got snowed over in the big storm."

"Some one broke through the crust before us," said Hamp, "for I saw the marks as I was falling."

"Then he's in here now, whoever he is," whispered Jerry, in a startled voice. "He couldn't have reached the hole to get out."

There was a moment of terrible silence. The boys huddled close together and shivered with fear. Their hearts beat loudly and rapidly.

"I don't hear anything," whispered Hamp. "Do you?"