Well, I thought that I could guess.
"Friends," said Yva, "it is time for us to be going and I am your guide.
You will meet the Lord Oro at the end of your journey.

I pray you to bring those lamps of yours with you, since all the road is not lightened like this place." "I should like to ask," said Bickley, "whither we go and for what object, points on which up to the present we have had no definite information." "We go, friend Bickley, deep into the bowels of the world, far deeper, I think, than any mortal men have gone hitherto, that is, of your race." "Then we shall perish of heat," said Bickley, "for with every thousand feet the temperature rises many degrees." "Not so.

You will pass through a zone of heat, but so swiftly that if you hold your breath you will not suffer overmuch.

Then you will come to a place where a great draught blows which will keep you cool, and thence travel on to the end." "Yes, but to what end, Lady Yva ?" "That you will see for yourselves, and with it other wondrous things." Here some new idea seemed to strike her, and after a little hesitation she added: "Yet why should you go?
Oro has commanded it, it is true, but I think that at the last he will forget.

It must be decided swiftly.