all squint towards our noses, but no normal person can turn
his eyes away from one another. My impression is that the presence or
absence, as the case might be, of a divergent squint would be accepted
as absolute disproof of identity. But here we are."

He inserted the key into the wicket of the large gate, and, when we had
stepped through into the covered way, he locked it from the inside.

"Why have you locked us in?" I asked, seeing that the wicket had a
latch.

"Because," he replied, "if we now hear any one on the premises we shall
know who it is. Only one person besides ourselves has a key."

His reply startled me somewhat. I stopped and looked at him.

"That is a quaint situation, Thorndyke. I hadn't thought of it. Why she
may actually come to the house while we are here; in fact, she may be in
the house at this moment."

"I hope not," said he. "We don't particularly want Mr. Weiss to be put
on his guard, for I take it, he is a pretty wide-awake gentleman under
any circumstances. If she does come, we had better keep out of sight. I
think we will look over the house first. That is of the most interest to
us. If the lady does happen to come while we are here, she may stay to
show us over the place and keep an eye on us. So we will leave the
stables to the last."

We walked down the entry to the side door at which I had been admitted
by Mrs. Schallibaum on the occasion of my previous visits. Thorndyke
inserted the latch-key, and, as soon as we were inside, shut the door
and walked quickly through into the hall, whither I followed him. He
made straight for the front door, where, having slipped up the catch of
the lock, he began very attentively to examine the letter-box. It was a
somewhat massive wooden box, fitted with a lock of good quality and
furnished with a wire grille through which one could inspect the
interior.

"We are in luck, Jervis," Thorndyke remarked. "Our visit has been most
happily timed. There is a letter in the box."

"Well," I said, "we can't get it out; and if we could, it would be
hardly justifiable."

"I don't know," he replied, "that I am prepared to assent off-hand to
either of those propositions; but I would rather not tamper with another
person's letter, even if that person should happen to be a murderer.
Perhaps we can get the information we want from the outside of the
envelope."

He produced from his pocket a little electric lamp fitted with a
bull's-eye, and, pressing the b