-a city like
ours! Down here, filled with octopi!..."

"Yes," answered Wells grimly, "and this 'city' may only be a small
settlement; there may be scores of these places. We'd better continue
ahead now that we're here; for we've got to get all the information we
can. I only hope these monsters haven't more than one big submarine.
We can expect an attack any minute...."

* * * * *

The _NX-1_ pressed on. The city dropped behind. A breathless tenseness
had settled down over the submarine; she was proceeding with utmost
caution, her anxious officers alert at the location chart. The great
fear that tormented them was that they might be attacked, not by one,
but by a fleet of the octopi ships....

Then, at the rim of the chart, a red dot appeared! It grew rapidly,
charging down on them at great speed. The spot was large; this was no
small sentry boat! At once the alarm bell shrilled its warning; the
crew below left their posts and raced to the control room. With sure
mechanical fingers the emergency system gripped the valve handles and
motor levers; Keith swung the _NX-1_ onto a level keel, straightened
her out, and decreased speed still more. Giving the rods of the motor
and rudder controls to Graham, he moved to the small lever which would
unleash his bow torpedoes, and fingered it lightly. The _NX-1_ was
ready for action.

Scarcely had the men reached the small control room than the familiar
electric charge tingled. They stared wonderingly at each other, half
afraid. No one seemed hurt. One hand on the torpedo lever, Wells
watched his charts and instruments. He thanked God that there was only
one of the enemy.

The ray's shock came again--and stronger. The red dot was practically
upon them. The screen was still empty. Coolly, Keith slowed the
submarine to a dead stop. The crimson stud came closer....

* * * * *

And then he saw it. It was the same fearsome, hulking form. The same
curving windows, dark and lifeless. The same knobs on its bow, one now
leaping and pulsing with the paralyzing glow. At a distance of a few
hundred feet the octopi ship swerved to a halt, dousing the NX-1 with
its ray unceasingly. Again those two underwater craft, so oddly
contrasted, were face to face. And again the weapon that had once
struck the American ship's crew down at their posts was directed full
onto the _NX-1_.

But it was harmless! It merely tingled, and did no