Rainey at once sprang to his feet, exclaiming: 

“Count me one to go hunt the beast, whatever it is.”

At once the others were on their feet shouting their eagerness for the hunt.

The Doctor chose a gob named Thompson to accompany Rainey on his “tiger hunt,” or whatever it might prove to be.  Rainey was well pleased at the choice, for Thompson was a sure shot and a cool, nervy hand in time of danger.

“If I don’t hear from you by morning,” said the Doctor, “I shall send a relief expedition.”

Rainey had fully recovered from the affair of the previous day.  Both he and Thompson had been among the guarding party that day, so were fresh and keen for work.  They found the moonlight making the wide stretches of ice and snow light as day.

“_ Some_ night and some game!” murmured Rainey, as they emerged from the tent.

* * * * *

When the men in native garb, who had stolen the submarine, lifted the hatch to take an observation, they were utterly unaware of the presence of two figures crouching behind the conning-tower.  This, in spite of the fact that the men wore their long knives strapped to their waists, gave Dave and the engineer a decided advantage—­an advantage they were not slow to make the most of.

Fortunately, the robbers crowded up the hatchway, all eager to catch a first view of the reputed gold valley, in which lay the treasure city.

As the third head peeped above the hatch, Jarvis sprang at them.  Swinging his ice-anchor, an ugly cudgel of bent iron with a chilled steel point, he sent two of the villains sprawling at a single blow.  Meanwhile, Dave, who had grappled with the third man, made a misstep and together they plunged down the hatchway.  His opponent landed full on Dave’s stomach, and so crushed the breath from him that for a second the lad could not move.  But instantly, he realized that he must act.  The man was attempting to draw his long knife.  Thrusting out a hand, Dave gripped the point of the blade in its soft leather sheath so tightly that it could not be withdrawn.

Struggling with every ounce of strength, the two men were rolling over and over on the deck.  The stranger was heavier and evidently older than Dave, but the American had one advantage.  He was dressed only in woolens.  The heavy skin clothing of his antagonist hampered his action.  In spite of this, Dave felt himself losing out in the battle.  The stranger’s hand was gripping closer and closer to his throat, and he felt his own hand losing its hold on the knife-blade, when he heard a welcome roar from the hatchway.  It was Jarvis.  With one leap he was at Dave’s side.  For an old man, he was surprisingly quick.  Yet, he was not too quick, for the murderous knife was swinging above Dave’s chest and a hand was at his throat, when Jarvis clove the assailant’s skull with his ice-anchor.

With a groan the man collapsed.  The knife clattered to the deck.  Jarvis dropped to the floor panting.