some fields, and they might know more in others. But their special knowledge enabled them to bridge the gap briefly—long enough to see us, and watch us—"

"And read our books." Red nodded.

"And perhaps learn our language—remember you got slapped."

"I'll watch it," said Red.

"There's no reason why the gap couldn't be bridged. Science and minds have done a lot of things that looked impossible."

We went to bed on that and all night long I dreamed of negative universes, with suns like old Sol except that they shone black in bright heavens and planets of space floating in vacuums of matter. Red must have dreamed about it too, because he had a question over the dehydrated ham and eggs the next morning.

"Does that explain the loss in mass for this asteroid?"

"I think it does. Either the method our minus counterparts have in bridging the gap, or perhaps some sort of space warp that permits them to do it. At any rate enough of the minus world has been projected through to our side of the equation to displace the mass of this planetoid. Our lab scales being haywire might be the result of a being's nearness to it, or something."

Red didn't digest it all, but I could see he was thinking. "I wonder what all this has to do with my whiskers," he mused.

We were busy making some further checks on the planetoid's mass later in the day when Red got a glimpse of the vision I'd seen. Red didn't take it quietly. He yelled loud and pointed.

I turned just in time to see her fade away. It was the same woman, dressed the same. But this time she had been a bit more than a vapor.

Red forgot where he was and made a dive toward her. His body shot like a bullet across the room, skimming over laboratory equipment, and his head crashed solidly against the telescope.

Red literally bounced back halfway again. Then a long thin arm seemed to reach out of nowhere and seize him by the jacket and hold him long enough to stop him.

Red drifted down to the floor, knocked cold.

It had happened so swiftly that I hadn't had time to move. Now I pulled myself toward Red. The arm was still there in space, and it had added a shoulder, a rather pretty shoulder. Next there was a body, clothed in the flowing orange cape, and finally a woman's head. It was the same one—the minus woman.

"It's true," I said.

The woman seemed to understand. "Yes," she said. "All that you told Red Brewer is true, Jay Hayling. For you, I am a minus woman. For me, you are a minus man. But we have bridged the gap. For the first time in eternity, plus and minus, positive and negative, can meet on even terms."

"Better not come too close," I said.

"Nothing will happen," she replied. "We are now alike." She stooped toward the fallen figure on the floor. "Help me with this child. He's unconscious."

"Child!" I said. "If he's a child, they grow 'em big in the minus world."

But as I lifted Jay off the floor I wondered if he was as big as I'd always thought. It wasn't his weight. Nothing weighed very much on this asteroid, but it was his frail body. He seemed to be a boy of sixteen, rather than a man stationed 300,000,000 miles in space.

I carried him out of the laboratory into the living quarters and placed him on his bunk. I loosened his clothing, noting at the time that he had been right about his garments not fitting him.

"You've made him lose weight," I said.

"What makes you think so?" the woman asked.

"Because every screwy thing that has happened since we came here a year ago must have an explanation."

The woman smiled. "Don't think too harshly of me." She looked very solid now. Her body had lost that tenuous look. She was no longer nebulous and cloud-like. "Certain things were necessary in order for me to proceed safely through the gap between the positive and negative worlds," she explained.

I looked at Red again. His face was smooth and I knew he hadn't shaved in more