back towards the house of mystery,
discussing the clerk's statements as we went.

"A very communicable young gentleman, that," Thorndyke remarked. "He
seemed quite pleased to relieve the monotony of office work with a
little conversation. And I am sure I was very delighted to indulge him."

"He hadn't much to tell, all the same," said I.

Thorndyke looked at me in surprise. "I don't know what you would have,
Jervis, unless you expect casual strangers to present you with a
ready-made body of evidence, fully classified, with all the inferences
and implications stated. It seemed to me that he was a highly
instructive young man."

"What did you learn from him?" I asked.

"Oh, come, Jervis," he protested; "is that a fair question, under our
present arrangement? However, I will mention a few points. We learn that
about six or seven months ago, Mr. H. Weiss dropped from the clouds into
Kennington Lane and that he has now ascended from Kennington Lane into
the clouds. That is a useful piece of information. Then we learn that
Mrs. Schallibaum has remained in England; which might be of little
importance if it were not for a very interesting corollary that it
suggests."

"What is that?"

"I must leave you to consider the facts at your leisure; but you will
have noticed the ostensible reason for her remaining behind. She is
engaged in puttying up the one gaping joint in their armour. One of them
has been indiscreet enough to give this address to some
correspondent--probably a foreign correspondent. Now, as they obviously
wish to leave no tracks, they cannot give their new address to the Post
Office to have their letters forwarded, and, on the other hand, a letter
left in the box might establish such a connection as would enable them
to be traced. Moreover, the letter might be of a kind that they would
not wish to fall into the wrong hands. They would not have given this
address excepting under some peculiar circumstances."

"No, I should think not, if they took this house for the express purpose
of committing a crime in it."

"Exactly. And then there is one other fact that you may have gathered
from our young friend's remarks."

"What is that?"

"That a controllable squint is a very valuable asset to a person who
wishes to avoid identification."

"Yes, I did note that. The fellow seemed to think that it was absolutely
conclusive."

"And so would most people; especially in the case of a squint of that
kind. We can