Leith did not allow me to remain long in the rear.  He called me up to the front, and very politely asked me to help in hustling along the carriers who were inclined to dawdle as the way grew rougher, and, although I would much rather have had the task of helping the two girls, I had to accept the position without demur.  Leith was in charge, and Holman and I were only intruders who had on standing, and whose food was paid for by the Professor.

We halted at midday in an ugly-looking spot far up the shoulder of the mountain that we were climbing, and through a break in the trees we caught a glimpse of the Pacific.  The ocean seemed directly beneath us, and yet, as Edith Herndon expressed it, we seemed to be a thousand leagues away from it.

[Illustration:  “We halted at midday in an ugly-looking spot far up the shoulder of the mountain.”]

“This horrible silence makes me long for the clean sound of the waves,” she whispered, as I rolled a stone over to make her a seat.  “This stillness stops one from speaking.  Do you know that Barbara and I haven’t spoken a word during the last hour?  We simply hadn’t the courage to make the effort.”

Under the watchful eye of Leith I endeavoured to cheer her up, while inwardly I cursed the prattling old Professor who chattered of the honours he expected as the rewards of his discoveries.  The affair was enough to bring tears to the eyes of a man with a heart of stone.

“I’m just thinking we should have stopped this business before it got this far,” muttered Holman, as he reached closer to get a light for his cigarette.

“What should we have done?” I asked.

“I don’t know,” he growled.  “We should have done something though.  Pity we didn’t lose Leith overboard with your friend Toni.”

“What’s wrong now?  Has anything happened?”

“No, nothing has happened,” he replied.  “I wish something would.  This silence is beginning to put my nerves on edge, but I’m afraid to yell out for fear that I might wake something that has been dead for centuries.  Does it strike you that way?”

“Very much.”

“Well, it’s the same with the girls,” muttered Holman.  “The stillness of the place has brought their ordinary conversational tone down to a whisper.”

Leith lurched across and interrupted our conversation.  “Get the boys going, Mr. Verslun,” he said.  “We want to cross the Vermilion Pit while the light is good, and it is hard going from here on.”

We started forward up the boulder-strewn slope, and with each step the difficulties of the ascent became greater.  I took an axe and helped Soma chop a path which would make it easier for the two sisters, but no matter what amount of trouble we took, they found it a difficult matter to follow.  Once, goaded into fury by Leith’s attempts to hurry the girls when Holman was assisting them over a particularly rough stretch, I turned upon the old scientist who was puffing along with the natives in the lead.