o one of those
underground tunnels Glanton says there are. Eh?" grinned Falkner, who
was fond of teasing his cousins.

"I wouldn't be having a quiet swim in it, for one thing. I think it's a
horrid place," answered the girl, while I for my part, mildly disclaimed
having made any such statement as that which he had attributed to me.

"Bosh!" he declared. "Why you can take splendid headers from the middle
rock there. Oh--good Lord!"

The exclamation was forcible, and to it was appended a sort of amazed
gasp from all who saw. And in truth I was not the least amazed of the
lot. For there was a disturbance in the depths of the pool. One
glimpse of something smooth, and sinuous, and shiny--something huge, and
certainly horrible--was all we obtained, as not even breaking the
surface to which it rose, the thing, whatever it might be--sank away
from sight.

"What was it?"

"Can't say for certain," I said, replying to the general query. "It
didn't come up high enough to take any shape at all. It might have been
a big python lying at the bottom of the hole, and concluding it had lain
there long enough came up, when the sight of us scared it down again.
I'm pretty sure it wasn't a crocodile."

"Tell you what, Glanton. You don't catch me taking any more headers in
there again in a hurry," said Falkner. "Ugh! If we'd only known!"

"There is prestige in the unknown," I said. "It may be something quite
harmless--some big lizard, or a harmless snake."

"Well it's dashed odd we should just have been talking of that very sort
of thing," said the Major. "Let's keep quiet now and watch, and see if
it comes up again."

We did, but nothing came of it. Indeed if I alone had seen the thing I
should have distrusted my senses, should have thought my imagination was
playing me false. But they had all seen it.

"I shall come down here again with the rifle and watch for an hour or
two a day," said Falkner. "Or how would it be to try bait for the
beast, whatever it is--eh, Glanton?"

"Well you might try to-morrow. Otherwise there isn't much time," I
answered. "We trek on Wednesday, remember."

Now all hands having grown tired of sitting there, on the watch for what
didn't appear, a homeward move was suggested, and duly carried out. We
had covered a good part of the distance when Miss Sewin made a
discovery, and an unpleasant one. A gold coin which was wont to hang on
her watch chain had disappeared.

"I must go b