ow, Keith ...
and--it won't be long! I've just a few minutes left...."

The faint words tapered into silence.

"No!" roared Keith in a great rush of emotion. But Hemmy's eager
voice came right back:

"Oh yes, you must! It would be a mercy to kill me, Keith."

There were tears in the commander's eyes. "Are you sure, Hemmy?" he
asked. "Are you sure?"

"Oh, yes. It would be a mercy."

Wells' lips formed a straight grim line. His words squeezed through it
tightly. "All right, Hemmy. Thanks. Thanks. I--I'll go after them now,
old man. I'll try and keep in touch with you through the duel, but
I--I can't promise--"

He could almost see Hemingway Bowman give his old familiar smile as he
answered:

"Then so long, Keith!"

* * * * *

Commander Keith Wells studied the teleview screen. The men were half
afraid to look at his strained blanched face.

Repeatedly the violet beam speared through the water, reaching for the
_NX-1's_ bow.

"Turn ship. Line up for stern torpedoes," the commander ordered
harshly. He realized he could not hold his submarine steady to obtain
a perfect sight, for the heat ray needed only thirty seconds to melt
through their shell. He would have to swing the ship slowly about;
and, as the shape of the enemy crossed the hair-lines on the
range-finder, unleash his torpedoes and gamble on hitting the moving
target.

The _NX-1_ swung around, always maintaining a slight forward motion
and zigzagging constantly to nullify the heat beam. Wells watched the
range-finder closely. The octopi ship slanted downwards, the deadly
violet ray stabbing from her bow. Slowly the black dot that
represented her appeared on the dial, and slowly it dropped towards
the crossed lines that showed the perfect firing point.

Keith grasped the torpedo lever. The _NX-1's_ stern was towards her
target. Dead silence hung in the control room. The _NX-1_ swung
slightly. The octopi craft appeared directly in the middle of the
dial.

Wells pulled back the lever.

The hiss of compressed air sprang from her stern. He had fired two
tubes, his whole stock of stern torpedoes. The pair of dreadful
weapons leaped out and settled on their course. Keith shot his gaze to
the teleview.

The torpedoes missed. Only by feet, but a miss all the same. They
raced on past the octopi submarine and, with a tremendous, ear-numbing
explosion, burst on the wall of the cavern beyond. Both ships reeled
from the sho