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 a note from O’Connor.  It was written with his usual brevity:  “Have just found from servants that Farrington and Mrs. P. have key to Vandam house.  Wish I had known it before.  House shadowed.  No one has entered or left it to-night.”

Craig looked at his watch.  It was a quarter after one.  “The ghost won’t walk to-night, Walter,” he said as he entered his bedroom for a much-needed rest.  “I guess I was right after all in getting the capsules as soon as possible.  The ghost must have flitted unobserved in there this morning directly after the maid brought them back from the druggist.”

Again, the next morning, he had me out of bed bright and early.  As we descended from the Sixth Avenue “L,” he led me into a peculiar little shop in the shadow of the “L” structure.  He entered as though he knew the place well; but, then, that air of assurance was Kennedy’s stock in trade and sat very well on him.

Few people, I suppose, have ever had a glimpse of this workshop of magic and deception.  This little shop of Marina’s was the headquarters of the magicians of the country.  Levitation and ghostly disappearing hands were on every side.  The shelves in the back of the shop were full of nickel, brass, wire, wood, and papier-mache contrivances, new and strange to the eye of the uninitiated.  Yet it was all as systematic as a hardware shop.

“Is Signor Marina in?” asked Craig of a girl in the first room, given up to picture post-cards.  The room was as deceptive as the trade, for it was only an anteroom to the storeroom I have described above.  This storeroom was also a factory, and half a dozen artisans were hard at work in it.