bring himself to open--that purpose was to use the reader, he would
swear to that. Tapes so left must have had a great importance for those
who left them. It was as if the whole valley was a trap to channel a
stranger into this underground chamber.

Travis snapped open the box, fed the first disk into the reader, and
applied his eyes to the vision tube at its apex.

The rippling walls looked just the same when he looked up once more, but
the cramp in his muscles told Travis that time had passed--perhaps hours
instead of minutes--since he had taken out the first disk. He cupped his
hands over his eyes and tried to think clearly. There had been sheets of
meaningless symbol writing, but also there had been many clear,
three-dimensional pictures, accompanied by a singsong commentary in an
alien tongue, seemingly voiced out of thin air. He had been stuffed with
ragged bits and patches of information, to be connected only by guesses,
and some wild guesses, too. But this much he did know--these towers had
been built by the bald spacemen, and they were highly important to that
vanished stellar civilization. The information in this room, as
disjointed as it had been for him, led to a treasure trove on Topaz
greater than he had dreamed.

Travis swayed on the bench. To know so much and yet so little! If Ashe
were only here, or some other of the project technicians! A treasure
such as Pandora's box had been, peril for one who opened it and did not
understand. The Apache studied the three walls of blue-purple-green in
turn and with new attention. There were ways through those walls; he was
fairly sure he could unlock at least one of them. But not now--certainly
not now!

And there was another thing he knew: The Reds must _not_ find this. Such
a discovery on their part would not only mean the end of his own people
on Topaz, but the end of Terra as well. This could be a new and alien
Black Death spread to destroy whole nations at a time!

If he could--much as his archaeologist's training would argue against
it--he would blot out this whole valley above and below ground. But
while the Reds might possess a means of such destruction, the Apaches
did not. No, he and his people must prevent its discovery by the enemy
by doing what he had seen as necessary from the first--wiping out the
Red leaders! And that must be done before they chanced upon the towers!

Travis arose stiffly. His eyes ached, his head felt stuffed with
pictures, hi