ight on the screen. For all its beauty, the Map
had a very useful purpose ... the registry and identification of
asteroid claims among the miners of Mars. Each asteroid registered as a
claim showed up as a red pinpoint; unclaimed asteroids were white. But
even with the advances of modern astronomy only a small percentage of
the existing asteroids were on the map, for the vast majority had never
been plotted.

Tom moved up to the Map and activated the magnifier. Carefully he
focussed down on the section of the Asteroid Belt they had visited so
recently. Dozens of pinpoints sprang to view, both red and white, and
beneath each red light the claim-number neatly registered. Tom peered at
the section, searching until he found the number of Roger Hunter's last
claim.

It was quite by itself, not a part of an asteroid cluster. He stepped up
the magnification, peered at it closely. There were a dozen other
pinpoints, all unclaimed, within a ten-thousand-mile radius....

But near it, nothing....

No hiding place.

And then, suddenly, he knew the answer. He stared at the Map, his heart
pounding in his throat. He cut the magnification, scanning a wide area.
Then he widened the lens still further, and checked the coordinates at
the bottom of the viewer.

He knew that he was right. He _had_ to be right. But this was no wild
dream, this was something that could be proved beyond any question of
error.

Across the room he picked up the phone to Map Control. It buzzed
interminably; then a sleepy voice answered.

"The Map," Tom managed to say. "It's recorded on time-lapse film, isn't
it?"

"'Course it is," the sleepy voice said. "Observatory has to have the
record. One frame every hour...."

"I've got to see some of the old film," Tom said.

"_Now?_ It's three in the morning."

"I don't need the film itself, just project it for me. There's a reader
here."

He gave the man the dates he wanted, Mars time. The man broke the
contact, grumbling, but moments later one of the film-viewers sprang to
life. The Map coordinates showed at the bottom of the screen.

Tom stared at the filmed image ... the image of a segment of the
Asteroid Belt the day before Roger Hunter had died.

It was there. When he had looked at the Map, he had seen a single red
pinpoint of light, Roger Hunter's asteroid, with nothing in the heavens
anywhere near it.

But on the film image taken weeks before there were two points of light.
One was red, with