the huge shape came forward; the impulse to leap back
to shelter was horribly strong, but Mart resisted it.

Around circled the shark, exposing its full length. Mart trembled at the
sight, for it seemed to him that the brute must be far longer than the
thirty feet which Jerry had assigned as its size. It stretched out
quivering in the depths, ghostly, ominous; and most terrible of all was
the silence that prevailed over all things. Mart wanted to shout, to
yell for aid, and could not.

Almost without warning, the great bulk swept around and came at him,
twisting about so that the gaping mouth could nip him as it swept past.
But Mart was ready; every nerve and muscle in his body was tensed up to
the highest pitch, and as the shark lunged forward, he swerved sharply
back to his shelter.

None too soon, indeed. The gray bulk swept down on him in a great swirl
that almost flung him off his feet; as he reeled, catching at the corner
of the wreck for support, he saw the rough, mottled skin shoot past
hardly a foot away. Mart swiftly jerked up his kris and lunged forward
with all his strength.

He felt the keen weapon shear into the brute and jerk him out, but he
grimly held to his grip. Something struck him and sent him staggering;
then he had pulled the kris free. Barely had he done so when the shark's
huge forked tail drove past his head in a lash of foam and blood, and
Mart reeled back into his shelter. The sides of the wreck caught his
shoulders and kept him upright, fortunately.

He noticed a slight roaring in his ears, and knew that the air was
beginning to get bad in his helmet. He pressed his diving dress and
forced up some of his remaining supply. Peering out, he could not
repress a thrill of exultation--he had won the first round!

Yet it was a strange and awe-inspiring sight that met his gaze. Tingeing
the water a dim red, the immense fish was tearing to and fro in wild
fury, lashing across the entrance like lightning, drawing the water in
swirls and whirlpools that came near to dragging out Mart despite his
grip on the wreck. He felt even the old ship tremble beneath the fierce
blast of water, while the huge gray shape flashed down and across and
up, back and forth, in terrible spasms of rage. But after it trailed
that thin stream of red, and Mart exulted.

"By golly, I've got to finish this thing quick!" he thought vaguely, for
the roaring in his ears had increased, and it was hard to fill his lungs
with