"'Don't speak to me,' he cried, as I ventured to interrupt him. 'I can
see it now. It is all plain. It was not the servant, but his master,
the Russian himself, and it was he who came back for the letters! He
came back for them because he knew they would convict him. We must
find them. We must have those letters. If we find the one with the
Russian postmark, we shall have found the murderer.' He spoke like a
madman, and as he spoke he ran around the room with one hand held out
in front of him as you have seen a mind-reader at a theatre seeking
for something hidden in the stalls. He pulled the old letters from the
writing-desk, and ran them over as swiftly as a gambler deals out
cards; he dropped on his knees before the fireplace and dragged out
the dead coals with his bare fingers, and then with a low, worried
cry, like a hound on a scent, he ran back to the waste-paper basket
and, lifting the papers from it, shook them out upon the floor.
Instantly he gave a shout of triumph, and, separating a number of torn
pieces from the others, held them up before me.

"'Look!' he cried. 'Do you see? Here are five letters, torn across in
two places. The Russian did not stop to read them, for, as you see, he
has left them still sealed. I have been wrong. He did not return for
the letters. He could not have known their value. He must have
returned for some other reason, and, as he was leaving, saw the
letter-box, and taking out the letters, held them together--so--and
tore them twice across, and then, as the fire had gone out, tossed
them into this basket. Look!' he cried, 'here in the upper corner of
this piece is a Russian stamp. This is his own letter--unopened!'

"We examined the Russian stamp and found it had been cancelled in St.
Petersburg four days ago. The back of the envelope bore the postmark
of the branch station in upper Sloane Street, and was dated this