as in Central Africa between the detective and his
quarry, when this amateur doctor came to the point of exercising his
healing art upon the fallen Zero.

"Well, Monckton Bassett, we meet again," said Kenyon, coolly; "and now
let me look at this head of yours, for I should be sorry for you to go
off the ropes without Uncle Sam having a hand in the affair."

For reply Zero hurled a fearful curse at the detective, and ordered him
to begone, so Kenyon calmly left the scoundrel to himself.

CHAPTER SEVENTEEN.

"QUOD DIXI DIXI."

As soon as opportunity offered, Grenville closely questioned the
Chieftain of the Stick as to the manner in which his party, commanded by
Leigh, had been expelled from the cavern, where all had thought them so
securely entrenched, and now it was that our friends received another
striking proof of Zero's intense cunning, and of the absolutely perfect
knowledge which the man possessed regarding the mountain fastnesses in
the immediate neighbourhood of his quarters.

Foolishly enough, the little band had failed to notice the singular fact
that the air in the cave was at all times fresh and crisp, instead of
being extremely heavy and "muggy," as is ordinarily the case in long,
unventilated caverns; and it was only now that they realised the truth,
which was that Muzi Zimba's home was situated in the very heart of an
immense volcano, which had been extinct for ages, but whose final
convulsions had probably torn the range in two, and formed the kloof, or
pass, of the Dark Spirit of Evil.

This fact, however, was perfectly well-known to their astute and
unscrupulous foe, and, appreciating his knowledge at its right strategic
value, and sending on by night a large party provided with an immense
rope-ladder, Zero had occupied the adjacent heights above and in the
rear of Leigh's position, and had actually dropped three hundred men
down through the very crater of the extinct volcano; and the first
intimation which the defenders of the cave had received of the presence
of this large force in their immediate rear, came to them in the
objectionable form of a well-aimed volley poured into their very backs
at point-blank range, just at the moment of the delivery, by Zero with
his main army, of a furious attack upon their defences in the mouth of
the cave.

To turn their attention to the force ambushed in their rear would, of
course, have been to let the slaver-chief in upon them, when the cavern
woul