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 button, threw a beam of light in through
the grille. The letter was lying on the bottom of the box face upwards,
so that the address could easily be read.