years, of course. And twenty feet away, oblivious of his
surroundings except for what was directly in front of him, was my man.

His height and build were somewhat less than the norm. But it was his
profile that drew my attention. A remarkable throwback; a throwback of a
distinct type.

In fact, he might well have served as the model in the types textbooks
labeled British. The resemblance was subtle. Only one trained to
differentiate would ever have noticed it.

I let my attention take in his whole figure. His elbows had a habit of
making fluttery movements when his exploring hands paused so that a
strange birdlike impression was given. Also an air of ungainliness in
the lines of the lean body, rather than the feline smoothness and grace
of the norm-blend. It was so in keeping with his features that it served
to strengthen the psycho diagnosis.

A throwback to an era ten thousand years in the past, and therefore, as
the textbooks say, prone to mental instability. It was no wonder that
the girl called Dotty had had the air of being perpetually worried!

She appeared now, from the far side of the ruin and approached the man.

He sensed rather than saw her and straightened up, every line of him
etched with excitement.

"Dotty!" he said. "I've found it. I've found the proof. I've been here
before, thousands of years ago when this wasn't a ruins. I _remember_."

The girl's manner reflected weariness, "Please, Herb. You've got to
forget all about it. You'll talk too much!"

His shoulders stiffened. "Don't worry. I won't talk until I have proof
to convince even them. Somewhere around here something lies buried.
Something I will be able to remember. They will dig where the rocks
haven't been touched for five thousand centuries and find what I say is
there."

Dotty was shaking her head. "No, Herb, If it were on Earth I might half
believe you. But not here on Mars. These--these people weren't even
humanoid!"

"_Neither was I_," Herb whispered hoarsely.

I sighed regretfully. I'd seen too many cases like this one. I'd grown
to dread them. But it was a job and a man had to eat.

* * * * *

The guide began herding the tourists back to the bus. I mingled with the
crowd, and when Dotty and Herb climbed aboard I managed to stick close
to them.

"Where'd you two go to?" the man in the pith helmet called from where he
was sitting. "Stick close to me. I put a new roll in the camera. At the