urple flame dropping rapidly toward the horizon. Darkness came
suddenly as that seething ball disappeared, and the air became bitterly
cold, in sharp contrast to the pleasant warmth of a moment before. And
as suddenly clouds appeared in blackly banked masses and a cold, driving
rain began to beat down in torrents.

"Br-r-r, it's cold! Let's go in--Oh! _Shut the door!_" Clio shrieked,
and leaped wildly down into the compartment below, out of Costigan's
way, for he and Bradley also had seen slithering toward them the
frightful arm of the Thing.

Almost before the girl had spoken Costigan had leaped to the levers, and
not an instant too soon; for the tip of that horrible tentacle flashed
into the rapidly narrowing crack just before the door clanged shut. As
the powerful toggles forced the heavy screw threads into engagement and
drove the massive disk home into its bottle-tight, insulated seat, that
grisly tip fell severed to the floor of the compartment and lay there,
twitching and writhing with a loathsome and unearthly vigor. Two feet
long the piece was, and larger than a strong man's leg. It was armed
with spiked and jointed metallic scales, and instead of sucking disks it
was equipped with a series of _mouths_--mouths filled with sharp
metallic teeth which gnashed and ground together furiously, even though
sundered from the horrible organism which they were designed to feed.

The little submarine shuddered in every plate and member as monstrous
coils encircled her and tightened inexorably in terrific, rippling
surges eloquent of mastodonic power; and a strident vibration smote
sickeningly upon Terrestrial eardrums as the metal spikes of the
monstrosity crunched and ground upon the outer plating of their small
vessel. Costigan stood unmoved at the plate, watching intently; hands
ready upon the controls. Due to the artificial gravity of the lifeboat
it seemed perfectly stationary to its occupants. Only the weird
gyrations of the pictures upon the lookout screens showed that the craft
was being shaken and thrown about like a rat in the jaws of a terrier;
only the gauges revealed that they were almost a mile below the surface
of the ocean already, and were still going downward at an appalling
rate. Finally Clio could stand no more.

"Aren't you going to do something, Conway?" she cried.

"Not unless I have to," he replied, composedly. "I don't believe that he
can really hurt us, and if I use a ray of any kind I'm afrai