forth similar views, which made me anxious to make his acquaintance."

"Are you suggesting that he should spend a night in this house?" I asked.

"I do not think I suggested such a thing," said Randall with a smile,
"but I believe that is the professor's intention."

"It is," said Quarles.

"When?" I asked.

"On Friday night."

"Greaves died on a Friday night," said Randall. "It is a small point,
perhaps, but, like myself, the professor believes in small details."

"I suppose the agent will let me have the key," said Quarles.

"I do not know the agent. I got the key through Dr. Bates, and I can give
you a card of introduction to him."

"It will be a very interesting experiment," I said, looking as learned as
I could. I thought I had kept my end up very well, and far from having to
pretend to be interested, as Quarles had suggested, I was profoundly
interested, not in the psychological discussion, but in the Bayswater
mystery. I had heard of it before, and remembered that Martin, one of the
oldest members of the force, had said that it was no more a case of
suicide than he was a raw recruit. I am far from saying that no mystery
is to be accounted for by the supernatural, but I always want to test it
in every other way first.