signal, and a second later a torrent of
water rushed out of the gratings to foam about their feet. They were
ready to leave Luralla!

Again they went through the maze of water-filled passages, passing
occasional sentries. After a while the character of the corridor
changed. It was wider, and was arched instead of square, and there was a
carpet of soft natural sand beneath their feet instead of a stone floor.

"We come to the last outpost of Luralla, _hiziren_!" the guide said.

They stepped out of the end of the passage and found themselves in the
open sea, many fathoms down. A broad and slightly sloping floor of
smooth sand studded with lumps of coral and clusters of sea-weed
stretched before them. Some were giant ferns stretching twelve and
fifteen feet high, others were low and sponge-like growths. A school of
tiny red fishes shot swiftly past them. Larger fish sailed majestically
by overhead. The top of the water was a gleaming golden ceiling far
above them, the greenish yellow light lessening in intensity as it came
down to the depths.

The end of the passage was surrounded by a barrier of piled coral.
Outlaw swordsmen stood on guard, also armed with a sort of compressed
air cross-bow that shot a heavy metal needle with great force. From a
corral at one side an orderly brought three saddle-dolphins.

The big fish were equipped with rubber saddles strapped around the body,
and short stirrups. They were guided by a bridle similar to that used on
Earthly horses. As Gerry swung up to the saddle his dolphin bucked once
or twice with quick flips of his tail, then steadied down as he felt the
tight pressure of his master's knees. When the other two were mounted,
the officer commanding the outpost lifted his arm in salute.

"The Dragon Gods be with you!" he said. At a distance of fifteen or
twenty feet the sound of his voice was slightly muted, but the words
were perfectly clear in the ear-pieces of Gerry's helmet. He lifted his
own rubber gloved hand to his globular helmet and returned the salute.

* * * * *

They rode off at an easy pace, the dolphins rising above the tops of the
tallest vegetation. Gerry found that it was easy to sit the saddle as
long as he bent a little forward to overcome the resistance of the water
against his chest. They were about thirty or forty feet down. On Earth
such a depth would have been uncomfortable, but the lighter gravity of
Venus made it easily b