bove, his own kind gathered. Hurriedly he
tapped out in code his warning in return.

Two dolphins busy again, their last dive over the dragon pushing the
monster down past Ross's niche toward the saucer's depths. Then they
flashed up and away. The dragon was rising in turn, but coming to meet
the Hawaikan creature was a ball giving off light, bringing sharp vision
and color with it.

Ross's arm swung up to shield his eyes. There was a flash; such
answering vibration carried through the waves that even his nerves, far
less sensitive than those of the life about him, reacted. He blinked
behind his mask. A fish floated by, spiraling up, its belly exposed. And
about him growths drooped, trailed lifelessly through the water; while
there was a now motionless bulk sinking to the obscurity of the
depression floor. A weapon perfected on Terra to use against sharks and
barracuda had worked here to kill what could have been more formidable
prey.

The Terran wriggled out of the niche, rose to meet another swimmer. As
Ashe descended, Ross relayed his news via the sonic. The dolphins were
already nosing into the depths in pursuit of their late enemy.

"Look here--" Ross guided Ashe to the crevice which had saved him, aimed
the torch beam into it. He had been right! There was a long groove in
the covering built up by the growths; a vertical strip some six feet
long, of a uniform gray, showed. Ashe touched the find and then gave the
alert via the sonic code.

"Metal or an alloy, we've found it!"

But what did they have? Even after an hour's exploration by the full
company, Ashe's expert search with his knowledge of artifacts and
ancient remains, they were still baffled. It would require labor and
tools they did not have, to clear the whole of the saucer. They could be
sure only of its size and shape, and the fact that its walls were of an
unknown substance which the sea could cloak but not erode. For the
length of gray surface showed not the slightest pitting or time wear.

Down at its centermost point they found the dragon's den, an arch coated
with growth, before which sprawled the body of the creature. That was
dragged aloft with the dolphins' aid, to be taken ashore for study. But
the arch itself ... was that part of some old installation?

Torches to the fore, they entered its shadow, only to remain baffled.
Here and there were patches of the same gray showing in its interior.
Ashe dug the butt of his spear-gun into the s