me to find how numerous the railway arches were in this part of London
and how continually the nature of the road-metal varied.

It was by no means a dull journey this time. The incessant changes of
direction and variations in the character of the road kept me most
uncommonly busy; for I had hardly time to scribble down one entry before
the compass-needle would swing round sharply, showing that we had once
more turned a corner; and I was quite taken by surprise when the
carriage slowed down and turned into the covered way. Very hastily I
scribbled down the final entry ("9.24. S.E. In covered way"), and having
closed the book and slipped it and the board into my pocket, had just
opened out the newspaper when the carriage door was unlocked and opened,
whereupon I unhooked and blew out the lamp and pocketed that too,
reflecting that it might be useful later.

As on the last occasion, Mrs. Schallibaum stood in the open doorway with
a lighted candle. But she was a good deal less self-possessed this time.
In fact she looked rather wild and terrified. Even by the candle-light
I could see that she was very pale and she seemed unable to keep still.
As she gave me the few necessary words of explanation, she fidgeted
incessantly and her hands and feet were in constant movement.

"You had better come up with me at once," she said. "Mr. Graves is much
worse to-night. We will wait not for Mr. Weiss."

Without waiting for a reply she quickly ascended the stairs and I
followed. The room was in much the same condition as before. But the
patient was not. As soon as I entered the room, a soft, rhythmical
gurgle from the bed gave me a very clear warning of danger. I stepped
forward quickly and looked down at the prostrate figure, and the warning