Quarles was pleased to jeer at me for a skeptic as we drove back to
Chelsea. He did not consider me altogether a fool as a detective, but he
had no use for me as a psychological student.

"Anyway, it is a pity you are undertaking this business in your present
nervous state," I said. "At least let me be with you on Friday night."

"Nonsense, that would make the experiment useless. You clear up the
mystery of this subtle scoundrel who has tried to get me shot and my
nervous state will soon disappear."

As a matter of fact, I couldn't settle to a careful study of my recent
cases, as the professor had suggested. I tried and failed. I could not
forget the experiment which was to be made on Friday night, and on
Wednesday morning I took action. First of all, I arranged that a special
constable should be on duty in Manleigh Road, and from his appearance no
one would have supposed that anything in the way of a genius had been
introduced into the neighborhood. He looked a fool; he was one of the
smartest men I knew. Strangely enough, on the Thursday night No. 7 was
burgled quite early in the evening as soon as it was dusk. Two men got in
at a basement window, and the constable was quite close at the time. He
had instructions, in fact, to give warning to the burglars if there was
any danger of their being seen.

I had not burgled the house alone; I had taken a young detective named
Burroughs with me. Of course, I might say it was because I wanted to give
him a chance, or because I thought we might encounter desperate
characters in the house; but as a fact, it was the supernatural element
which decided me. I do not like the idea of the supernatural; my nerves,