pected."

"Why, sir?" said Adam. "Is the killing of a mongoose--no matter by
whom--so serious a thing as all that?"

His companion smoked on quietly for quite another few minutes before he
spoke.

"When I have properly thought it over I may moderate my opinion, but in
the meantime it seems to me that there is something dreadful behind all
this--something that may affect all our lives--that may mean the issue of
life or death to any of us."

Adam sat up quickly.

"Do tell me, sir, what is in your mind--if, of course, you have no
objection, or do not think it better to withhold it."

"I have no objection, Adam--in fact, if I had, I should have to overcome
it. I fear there can be no more reserved thoughts between us."

"Indeed, sir, that sounds serious, worse than serious!"

"Adam, I greatly fear that the time has come for us--for you and me, at
all events--to speak out plainly to one another. Does not there seem
something very mysterious about this?"

"I have thought so, sir, all along. The only difficulty one has is what
one is to think and where to begin."

"Let us begin with what you have told me. First take the conduct of the
mongoose. He was quiet, even friendly and affectionate with you. He
only attacked the snakes, which is, after all, his business in life."

"That is so!"

"Then we must try to find some reason why he attacked Lady Arabella."

"May it not be that a mongoose may have merely the instinct to attack,
that nature does not allow or provide him with the fine reasoning powers
to discriminate who he is to attack?"

"Of course that may be so. But, on the other hand, should we not satisfy
ourselves why he does wish to attack anything? If for centuries, this
particular animal is known to attack only one kind of other animal, are
we not justified in assuming that when one of them attacks a hitherto
unclassed animal, he recognises in that animal some quality which it has
in common with the hereditary enemy?"

"That is a good argument, sir," Adam went on, "but a dangerous one. If
we followed it out, it would lead us to believe that Lady Arabella is a
snake."

"We must be sure, before going to such an end, that there is no point as
yet unconsidered which would account for the unknown thing which puzzles
us."

"In what way?"

"Well, suppose the instinct works on some physical basis--for instance,
smell. If there were anything in recent juxtaposition to the attacked
which would car