I had hung up the receiver scarce a moment when, acting upon a
sudden determination, I called up New Scotland Yard, and asked for
Detective-Inspector Bristol, whom I knew well. A few words were
sufficient keenly to arouse his curiosity, and he announced his
intention of calling upon me immediately. He was in charge of the
case of the severed hand.

I made no attempt to resume work in the interval preceding his
arrival. I had not long to wait, however, ere Bristol was ringing
my bell; and I hurried to the door, only too glad to confide in one
so well equipped to analyze my doubts and fears. For Bristol is no
ordinary policeman, but a trained observer, who, when I first made
his acquaintance, completely upset my ideas upon the mental
limitations of the official detective force.

In appearance Bristol suggests an Anglo-Indian officer, and at the
time of which I write he had recently returned from Jamaica and his
face was as bronzed as a sailor's. One would never take Bristol
for a detective. As he seated himself in the armchair, without
preamble I plunged into my story. He listened gravely.

"What sort of house is Professor Deeping's?" he asked suddenly.

"I have no idea," I replied, "beyond the fact that it is somewhere
in Dulwich."

"May I use your telephone?"

"Certainly."