light. I held my breath and listened. And I heard the faint scraping of the knife against stone.

I wished fervently that I had a standard C.I. infrascope so that I could see. Steve probably knew more of what was going on than I did. I had counted on watching Herb by his own black light pencil, and he was working in darkness.

Carefully I stole forward, inch by slow inch, my ears tuned for the faintest significant sound such as a grunt of satisfaction that would tell of finding what he was digging for.

And a million thoughts taunted me, thoughts about the latest discoveries in disintegration frequencies, thoughts about how little we knew of that ancient Martian civilization.

But also I was figuring what Herb would do. He would find the object he was digging for. Unwittingly he would grunt his triumph. Dotty might forget his strict warnings to be quiet, and say something. Regardless of that, he would stand up slowly, fondling what he had found, remembering what it was and how it worked. There would be a few seconds before it would become a weapon in his hands, seconds that I had to make the most use of, and be ready for.

"Uh!" It was the triumphant grunt I had known would come.

Sudden panic made me cast aside whatever vague plan of action I had had.

I turned on my pencil, bathing the two in its black light. At the same time I said, "I thought it was a scheme to get rid of me."

It was the element of surprise that saved me. A still picture of the scene the black light disclosed etched itself into my mind. There was an object in Herb's hand. A strange, meaningless object, dirty, yet with definite form. It was cradled in his hand like a weapon. It was pointed almost at me.

I dropped my pencil and went in low, diving for his legs. I felt the air crackle where I had just stood. As my arms encircled his legs I heard thunder exploding nearby.

Training has its advantages. The moment I felt contact with Herb that training took over. I jerked and rolled in a movement calculated to throw him to the ground face down, the motion ending in a backbreaker hold.

But only a part of my mind was concerned with that. The other part was frozen with horror. Approximately a half acre of the cemetery was glowing. I saw Steve in the center of it with Herb's weapon pointing his way. The very inertia of matter held Steve together for that brief instant, then he was falling apart, melting and evaporating at the same time, just like the stone markers and the ground around him.

I had the thing away from him suddenly, and I wondered what to do next. Running footsteps gave me the answer. It was other C.I. agents closing in.

Seconds later they had Herb under control. Dotty was wringing her hands and crying.

Me, I was holding the thing, afraid to let go of it and afraid to keep on holding it. But as the seconds passed without it exploding into destructive action again I began to let myself think I might live a while longer.

The area of destruction was molten now. Its heat was like that of an open blast furnace.

We skirted it and headed toward the road, lights in the distance telling us that cars were on the way to get us.

I saw Dotty stumble. I took her arm. She looked up at me, recognized me in the light from the glowing pool of bubbling lava, and tried to pull away.

"Take it easy," I said gruffly. "I'm your friend. Maybe the only friend you've got here."

Her look told me she didn't believe me, but she didn't pull away any more.

We walked along, and after a moment she seemed to struggle up out of her mental paralysis.

"Herb was right!" she said in a low, wondering tone. "He really did remember."

"It was plain coincidence," I said sharply, "and don't ever let yourself think differently. He's insane. It's a recognized form of insanity. He'll be sent to a good mental hospital, and in a year or two he'll come out good as new."

"Coincidence?" she echoed. Then she laughed. It was