“Not very hearty eatin’, ‘cordin’ to my way of thinkin’,” said Bill; “but I guess with that and the moss Dirola can dig up we’ll get along.”

The Esquimaux woman had finished her simple meal.  She dug up quite a quantity of the moss and laid it on top of a big pile of ice, where she could find it again.

“Must build house now,” she announced.  “Make place for sleep.  I show you!”

In a little while a large space was scooped out of the snow drift.  Many hands soon enlarged the cave until it was large enough for all to move about inside with comfort.

“Now for dinner!” exclaimed Jack, as he opened the tin.

The meal, though simple, was satisfying, and soon the lost ones felt more comfortable.

“It’s stopped snowing!” announced Mark, going to the entrance of the cave, “and it’s much colder.  I guess we’ll stay here a while.”

He returned to his companions.  They all went as far to the rear of the cave as they could, for the wind came in the wide entrance.

“We must make a winding passage, and then the breeze can’t find it’s way in,” suggested Jack.  “I think—­”

But what he thought he never told, for at that instant the floor of the snow cave gave way right under where they were all standing, and the whole five of them went slipping, sliding and tumbling down, they knew not to where.

For an instant all were so surprised and frightened that they could not even cry out.  They were plunged into dense blackness.

“What has happened?” Jack cried.

Before any one could answer him, the blackness gave way to a glare of light, and the two boys, with Dirola and the men, brought up suddenly with a jolt on the floor of a big ice cavern.

It was several hundred feet long, and as many wide, with a roof fifty feet above their heads.

The sides were of pure ice, but, strangest of all, was the rosy, golden glow that filled the whole place.  With wonder in their eyes the adventurers gazed at the source of the illumination.

At one end of the cavern was a rude altar.  Behind it, and on both sides, there arose great streamers of fire, tongues of flame, red, green, blue, purple, yellow and glaring white.

Yet the fire did not burn, for there was ice on every side, and the ice did not melt.  In wonder the crew of the Monarch gazed.

Presently from the other end of the cave there sounded a wild, weird song.  It was like a chant.  Then, before the adventurers could get to there feet, there filed into the cavern two score of men, all dressed in white fur.  At the head of the procession marched two men who were veritable giants, compared to those about them.  They bore between them, on a rude litter, a man, wearing only a fur cloth about his middle.

“What is it?” whispered Jack in awed accents.

“They are fire-worshipers!” exclaimed Mark.  “If they see us they’ll kill us!”