ion. 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
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