we walked, and the side or wall that
our hands touched. Nor was this because of darkness, since although it
was not illuminated like the upper caverns, light of a sort was present.
It was a very strange light, consisting of brilliant and intermittent
flashes, or globes of blue and lambent flame which seemed to leap from
nowhere into nowhere, or sometimes to hang poised in mid air.

"How odd they are," said the voice of Bastin behind me. "They remind
me of those blue sparks which jump up from the wires of the tramways in
London on a dark night. You know, don't you, Bickley? I mean when the
conductor pulls round that long stick with an iron wheel on the top of
it."

"Nobody but you could have thought of such a comparison, Bastin,"
answered Bickley. "Still, multiplied a thousandfold they are not
unlike."

Nor indeed were they, except that each blue flash was as big as the full
moon and in one place or another they were so continuous that one could
have read a letter by their light. Also the effect of them was ghastly
and most unnatural, terrifying, too, since even their brilliance could
not reveal the extent of that gigantic hollow in the bowels of the
world wherein they leapt to and fro like lightnings, or hung like huge,
uncanny lanterns.

Chapter XXV. Sacrifice

"The air in this place must be charged with some form of electricity,
but the odd thing is that it does not seem to harm us," said Bickley
in a matter-of-fact fashion as though he were determined not to be
astonished.

"To me it looks more like marsh fires or St. Elmo lights, though how
these can be where there is no vapour, I do not know," I answered.

As I spoke a particularly large ball of flame fell from above. It
resembled a shooting star or a meteor more than anything else that I
had ever seen, and made me wonder whether we were not perhaps standing
beneath some inky, unseen sky.

Next moment I forgot such speculations, for in its blue light, which
made him terrible and ghastly, I perceived Oro standing in front of us
clad in a long cloak.

"Dear me!" said Bastin, "he looks just like the devil, doesn't he, and
now I come to think of it, this isn't at all a bad imitation of hell."

"How do you know it is an imitation?" asked Bickley.

"Because whatever might be the case with you, Bickley, if it were, the
Lady Yva and I should not be here."

Even then I could not help smiling at this repartee, but the argument
went no further for Oro h