again. Bob, our location chart shows the presence
of some strange undersea metallic body. It can't be a submarine, for
my maritime reports would show its presence. We think it has some
connection with the 'machine-fish' that survivor raved about. At any
rate, I'm going after it. The world has a right to know what destroyed
that fishing fleet, and since the _NX-1_ is right on the spot it's my
duty to track it down. Re-broadcast this news to land stations, will
you? I'll keep in touch with you."

Knapp's voice came soberly back. "I guess you're right, Keith; it's up
to you.... So long, old man. Good luck!"

* * * * *

In Wells' veins throbbed the lust for action. With control studs at
hand, location chart and teleview screen before his eyes and fifteen
men waiting below for his commands, he had no fear of any monster the
underseas might spew up. He glanced swiftly at the location chart and
depth indicator again.

The mysterious red spot was slowly coming across the _NX-1's_ bows at
a distance of about one mile. Keith punched a stud, and, as his craft
filled her tank and slipped down further into deep water, he spoke to
Hemmy Bowman.

"Take control for a minute. Keep on all speed, and follow 'em like a
bloodhound. I'm going below."

He strode down the connecting ramp to the lower deck, where he found
fifteen men standing vigilantly at posts. At once Keith plunged into a
full explanation of what he had learned up in the control room. He
concluded:

"A great moral burden rests on us--every one of us--as we will soon
come face to face with a possible world menace. Anything may happen. A
state of war exists on this submarine. You will be prepared for any
wartime eventuality!"

Sobered faces greeted this announcement, and perceptibly the men
straightened and held themselves more alertly. Wells at once returned
to the control room. A glance at the location chart and its two tiny
lights told him that the intervening distance had been decreased to
about half a mile.

The depth dial showed them both to be two miles below, and steadily
diving lower. Charts showed the sea-floor to be three miles deep in
this position, and that meant--

"Look there!" exclaimed the first officer suddenly. "It's changing
course!"

* * * * *

The crimson stud had suddenly shifted its course, and now was fleeing
directly before them. For a moment the distance between the green