"Ach, so you always say!" he exploded, but without genuine wrath. "Why must the burden of proof rest with the spirits? How can you prove that they do not live and move and act? Study what Eddington has to say about that."

"For five years," I reminded him, "I have offered a prize of five thousand dollars to any medium whose spirit miracles I could not duplicate by honest sleight-of-hand."

He gestured with slim fingers, as though to push the words back into me. "That proves absolutely nothing, Wills. For all your skill, do you think that sleight-of-hand can be the only way? Is it even the best way?"

"I've unmasked famous mediums for years, at the rate of one a month," I flung back. "Unmasked them as the clumsiest of fakes."

"Because some are dishonest, are all dishonest?" he appealed. "What specific thing would convince you, my friend?"

I thought for a moment, gazing at him through the billows of smoke. Not a gray hair to him—and I, twenty years his junior, had six or eight at either temple. I went on to admire and even to envy that pointed trowel of beard, the sort of thing that I, a magician, might have cultivated once. Then I made my answer.

"I'd ask for a materialization, Doctor. An ectoplasmic apparition, visible and solid to touch—in an empty room with no curtains or closets, all entrances sealed by myself, the medium and witnesses shackled." He started to open his mouth, but I hurried to prevent him. "I know what you'll say—that I've seen a number of impressive ectoplasms. So I have, perhaps, but not one was scientifically and dispassionately controlled. No, Doctor, if I'm to be convinced, I must make the conditions and set the stage myself."

"And if the materialization was a complete success?"

"Then it would prove the claim to me—to the world. Materializations are the most important question in the whole field."

He looked long at me, narrowing his shrewd eyes beneath the dark single bar of his brows. "Wills," he said at length, "I hoped you would ask something like this."