“And wipe out Nordhu and the spider,” added Seymour.

“Do you think it wise?” Mervyn asked, “to penetrate again into the dens of the wolf-men? You may not get off so easily another time.”

“Wise or not,” returned the baronet doggedly, “I have given my word to the Ayuti and I shall keep it. Of course, if you do not care to come——”

“You know me better than that,” the scientist replied warmly; “we have passed through too many perils together for you to deem me a coward. Old though I am, I can still do my share when it comes to fighting.”

“Forgive me, old man,” murmured Seymour penitently; “I did not mean to suggest for a moment that I doubted your courage. You know that!”

“Ay, I know, my friend,” was Mervyn’s reply; “don’t think I’m offended by your words. But now let us push forward. The sooner we find Garth the better.”

One last sight they had of the azure dome above them, of the verdure-clothed walls of the ancient crater, then they plunged once more into the darkness of the tunnel, eager to begin the search for their missing comrade.

It was well that no presentiment of all that was to come crossed their minds, no subtle warnings of the perils that awaited them, through which they must pass ere they saw the daylight again, or even their bold spirits might have quailed before the prospect. As it was, knowing nothing, fearing nothing, they moved cheerily onward, making the tunnel ring with their jests and laughter.

* * * * * *

The underworld once more. At the foot of the cliff stairway stood the four explorers, awaiting their guide, who was seeking his elk and the hounds. At intervals they heard his piercing call, ringing out clear through the death-like silence of the place. And not for long did the Ayuti call in vain. Of a sudden a clamorous baying broke out, punctuated by the bellowing of Muswani, and through the twilight, from the direction of the distant lake, came the Ayuti’s pets.