“It’s empty,” I said.

“Stick your finger in it.”

I obeyed, and was aware of a sensation of cool moistness.  On withdrawing my hand I glanced at the forefinger, the one I had immersed, but it had disappeared.  I moved and knew from the alternate tension and relaxation of the muscles that I moved it, but it defied my sense of sight.  To all appearances I had been shorn of a finger; nor could I get any visual impression of it till I extended it under the skylight and saw its shadow plainly blotted on the floor.

Lloyd chuckled.  “Now spread it on, and keep your eyes open.”

I dipped the brush into the seemingly empty pot, and gave him a long stroke across his chest.  With the passage of the brush the living flesh disappeared from beneath.  I covered his right leg, and he was a one-legged man defying all laws of gravitation.  And so, stroke by stroke, member by member, I painted Lloyd Inwood into nothingness.  It was a creepy experience, and I was glad when naught remained in sight but his burning black eyes, poised apparently unsupported in mid-air.

“I have a refined and harmless solution for them,” he said.  “A fine spray with an air-brush, and presto!  I am not.”

This deftly accomplished, he said, “Now I shall move about, and do you tell me what sensations you experience.”

“In the first place, I cannot see you,” I said, and I could hear his gleeful laugh from the midst of the emptiness.  “Of course,” I continued, “you cannot escape your shadow, but that was to be expected.  When you pass between my eye and an object, the object disappears, but so unusual and incomprehensible is its disappearance that it seems to me as though my eyes had blurred.  When you move rapidly, I experience a bewildering succession of blurs.  The blurring sensation makes my eyes ache and my brain tired.”

“Have you any other warnings of my presence?” he asked.

“No, and yes,” I answered.  “When you are near me I have feelings similar to those produced by dank warehouses, gloomy crypts, and deep mines.  And as sailors feel the loom of the land on dark nights, so I think I feel the loom of your body.  But it is all very vague and intangible.”

Long we talked that last morning in his laboratory; and when I turned to go, he put his unseen hand in mine with nervous grip, and said, “Now I shall conquer the world!” And I could not dare to tell him of Paul Tichlorne’s equal success.

At home I found a note from Paul, asking me to come up immediately, and it was high noon when I came spinning up the driveway on my wheel.  Paul called me from the tennis court, and I dismounted and went over.  But the court was empty.  As I stood there, gaping open-mouthed, a tennis ball struck me on the arm, and as I turned about, another whizzed past my ear.  For aught I could see of my assailant, they came whirling at me from out of space, and right well was I peppered with them.  But when the balls already flung at me began to come back for a second whack, I realized the situation.  Seizing a racquet and keeping my eyes open, I quickly saw a rainbow flash appearing and disappearing and darting over the ground.  I took out after it, and when I laid the racquet upon it for a half-dozen stout blows, Paul’s voice rang out: