left you?"

"I don't think so," he replied, regarding the beaker and not his answer.
"Now, Walter, old fellow, I don't want you to be offended with me,
but really I can work better if you don't constantly remind me of such
things as eating and sleeping. Say, do you want to help me--really?"

"Certainly. I am as interested in the case as you are, but I can't make
heads or tails of it," I replied.

"Then, I wish you would look up Mrs. Popper to-night and have a private
seance with her. What I want you to do particularly is to get a good
idea of the looks of the room in which she is accustomed to work. I'm
going to duplicate it here in my laboratory as nearly as possible. Then
I want you to arrange with her for a private 'circle' here to-morrow
night. Tell her it is with a few professors at the university who are
interested in psychical research and that Mr. Vandam will be present.
I'd rather have her come willingly than to force her to come.
Incidentally watch that manager of hers, Farrington. By all means he
must accompany her."

That evening I dropped casually in on Mrs. Popper. She was a woman
of great brilliance and delicacy, both in her physical and mental
perceptions, of exceptional vivacity and cleverness. She must have
studied me more closely than I was aware of, for I believe she relied on
diverting my attention whenever she desired to produce one of her really
wonderful results. Needless to say, I was completely mystified by her
performance. She did spirit writing that would have done credit to the
immortal Slade, told me a lot of things that were true, and many more
that were unverifiable or hopelessly vague. It was really worth much
more than the price, and I did not need to feign the interest necessary
to get her terms for a circle in the laboratory.

Of course I had to make the terms with Farrington. The first glance
aroused my suspicions of him. He was shifty-eyed, and his face had a
hard and mercenary look. In spite of, perhaps rather because of, my
repugnance we quickly came to an agreement, and as I left the apartment
I mentally resolved to keep my eye on him.

Craig came in late, having been engaged in his chemical analyses all the
evening. From his manner I inferred that they had been satisfactory,
and he seemed much gratified when I told him that I had arranged
successfully for the seance and that Farrington would accompany the
medium.

As we were talking over the case a messenger arrived with