"Poor Herby," Dotty said.

"Yeah, poor Herby," Herb said with every appearance of tiredness and defeat. "But--that's that. Sorry to have gotten you all excited about nothing, Joe. Guess it was too much to expect anything." He turned to Dotty. "As long as we're out here, let's take a walk by ourselves. Huh?"

That was as obvious a cue as I had ever been handed. Neat. I was confronted with the alternatives of scramming or calling him a liar.

"Guess I might as well go back to the hotel," I said cheerfully. "See you in the morning."

I headed back the way we had come until I was sure they couldn't hear me or see me with their black light pencils. Then, ducking down next to a marker I waited. After a couple of minutes I heard cautious footsteps.

"It's me, Joe--Steve."

"Good," I grunted. "What are they doing now? They gave me the brush-off."

"I got the play," Steve said. "Slick. Should we close in now, or wait?"

"I think I'll play my part a little further. Don't want C.I. to think we're timid."

"Okay," Steve said. "The next funeral we attend may be our own."

"Yeah," I said. "It might."

I moved into the darkness, not using my black light pencil, but keeping my sensitized gla.s.ses on so I could see Herb's if I got close enough.

I reached the spot where we had done the digging. I hesitated, then kept on, toward the spot where Herb and Dotty had been so engrossed that afternoon. In my mind's eye I knew exactly where it was.

My hands explored ahead of me, searching out each stone marker along my path, clinging to it as I pa.s.sed it, and slipping off as I went on to the next. They were my only contact with reality in this total blackness.

I was thinking, too. I was thinking of what Herb had said about this being a parking area for airsleds back before the earliest known records of man on Earth when this city was alive. He was probably right about it at that. a.n.a.lysis had shown the presence of copper and aluminum in the top surface of some of the markers that could only be accounted for by some metallic object setting atop each one long ago, and remaining so that molecular and atomic creep could set in, carrying such atoms deep into the surface crystals of the stone.

And I was wondering what it was he hoped to dig up. If it were some sort of weapon it probably wouldn't work after all this time. It couldn't! Or could it? A few things had been pieced together about the ancient Martian civilization. Not much, but enough to be sure that they knew a few things we had never discovered. They had been masters at creating machines with no moving parts. The electronic devices we had found had proven they knew far more about V.H.F. than we did.

I could see what C.I. was aiming at now. We might not even recognize what Herb was searching for. It would be better to let him find it, and get it from him before he could use it. If it was a weapon.

And it probably was a weapon. I was pretty sure his main objective was hidden in the wall in the dome, and that this thing in the cemetery was something that would help him get to that objective.

My thoughts came back to my surroundings. I was less than a dozen feet from where Herb and Dotty should be. I stopped. There was no trace of black light. I held my breath and listened. And I heard the faint sc.r.a.ping 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 pa.s.sed 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 mirth that drifted quickly into hysterical hopelessness. I dug my fingers into her flesh until the pain brought her to her senses.

"Coincidence," I said. "Nothing more. I've seen seventeen cases just like his. How else did I spot him? I recognized the type. None of the others found what they rationalized themselves into thinking they remembered from the time they were Martians. Eventually one of them would stumble onto something. That's coincidence. Not incarnated memory."

She turned her head and blinked at me. I nodded grimly. "I'm an agent,"

I said. "I go out on the tours for one purpose only--to spot psychos and make sure they don't get out of control. You'd be surprised how many there are. Some of them, like your husband, probably show no sign of instability until they get here. They look around at the evidence of a civilization that existed before _h.o.m.o sapiens_ had evolved on the Earth, and it throws them. If you want to understand more about it read the medical books. They get irrational pre-memories. They look at something and the idea of familiarity a.s.sociates with the new impression. They look around a corner and see something, and build up the conviction that they had consciously known what was there before they looked around the corner."

I felt that I was making headway with her. I wanted to. I had to.

"You--you say there were others, and they didn't find anything?" she said. She was groping for something logical to grasp. I had to give her that something.

"That's right," I said. "And the law of averages said that someday someone would uncover something that's been missed."

She was nodding slowly now, accepting what I was saying. It was authoritative. She would find confirmation in authoritative books. If she wanted to pursue the subject she would find plenty of evidence, real evidence, to support it. It is a common form of insanity. It was important that she believe that.