"That is well thought of," said Thorndyke. "We had better take a lamp
with us. Let us go up to the laboratory and get one from Polton."

"There is no need to do that," said I. "The pocket-lamp that you lent me
is in my overcoat pocket. I put it there to return it to you."

"Did you have occasion to use it?" he asked.

"Yes. I paid another visit to the mysterious house and carried out your
plan. I must tell you about it later."

"Do. I shall be keenly interested to hear all about your adventures. Is
there plenty of candle left in the lamp?"

"Oh yes. I only used it for about an hour."

"Then let us be off," said Thorndyke; and we accordingly set forth on
our quest; and, as we went, I reflected once more on the apparent
vagueness of our proceedings. Presently I reopened the subject with
Thorndyke.

"I can't imagine," said I, "that you have absolutely nothing in view.
That you are going to this place with no defined purpose whatever."

"I did not say exactly that," replied Thorndyke. "I said that I was not
going to look for any particular thing or fact. I am going in the hope
that I may observe something that may start a new train of speculation.
But that is not all. You know that an investigation follows a certain
logical course. It begins with the observation of the conspicuous facts.
We have done that. The facts were supplied by Marchmont. The next stage