iss."

"They are a pretty pair, Thorndyke," I exclaimed. "A human life seems to
be no more to them than the life of a fly or a beetle."

"No; that is so. They are typical poisoners of the worst kind; of the
intelligent, cautious, resourceful kind. They are a standing menace to
society. As long as they are at large, human lives are in danger, and it
is our business to see that they do not remain at large a moment longer
than is unavoidable. And that brings us to another point. You had better
keep indoors for the next few days."

"Oh, nonsense," I protested. "I can take care of myself."

"I won't dispute that," said Thorndyke, "although I might. But the
matter is of vital importance and we can't be too careful. Yours is the
only evidence that could convict these people. They know that and will
stick at nothing to get rid of you--for by this time they will almost
certainly have ascertained that the tea-shop plan has failed. Now your
life is of some value to you and to another person whom I could mention;
but apart from that, you are the indispensable instrument for ridding
society of these dangerous vermin. Moreover, if you were seen abroad and
connected with these chambers, they would get the information that their
case was really being investigated in a businesslike manner. If Weiss
has not already left the country he would do so immediately, and if he
has, Mrs. Schallibaum would join him at once, and we might never be able
to lay hands on them. You must stay indoors, out of sight, and you had
better write to Miss Gibson and ask her to warn the servants to give no
information about you to anyone."

"And how long," I asked, "am I to be held on parole?"

"Not long, I think. We have a very promising start. If I have any luck,
I shall be able to collect all the evidence I want in about a week. But
there is an element of chance in some of it which prevents me from
giving a date. And it is just possible that I may have started on a
false track. But that I shall be able to tell you better in a day or
two."

"And I suppose," I said gloomily, "I shall be out of the hunt
altogether?"

"Not at all," he replied. "You have got the Blackmore case to attend to.
I shall hand you over all the documents and get you to make an orderly
digest of the evidence. You will then have all the facts and can work
out the case for yourself. Also I shall ask you to help Polton in some
little operations which are designed to throw light into d