s of low caves, where masses of
softer rock had been eaten out from beneath a slanting stratum of more
enduring material. The most spacious of these caves was immediately
behind the wreck. It was exactly what the monster craved. He backed into
it with alacrity, completely filling it with his spectral and swollen
body. In the doorway the convex inky lenses of his eyes kept watch,
moveless and all-seeing. And his ten pale-spotted tentacles, each
thicker at the base than a man's thigh, lay outspread and hidden among
the seaweeds, waiting for such victims as might come within reach of
their lightning snap and coil.

[Illustration: "A SINGULAR FIGURE, DESCENDING SLOWLY THROUGH THE
GLIMMERING GREEN."]

The monster had no more than got himself fairly installed in his new
quarters, when into the range of his awful eyes came a singular figure,
descending slowly through the glimmering green directly over the wreck.
It was not so long as the swordfish he had lately swallowed, but it was
thick and massive-looking; and it was blunt at the ends, unlike any
fish he had ever seen. Its eyes were enormous, round and bulging. From
its head and from one of its curious round, thick fins, extended two
slender antennae straight up toward the surface, and so long that their
extremities were beyond the monster's vision. It was indeed a
strange-looking creature, but he felt sure that it would be very good to
eat. In their concealment among the many-coloured seaweeds his tentacles
thrilled with expectancy, and he waited, like some stupendous nightmare
of a spider, to spring the moment the prey came within reach.

It chanced, however, that just as the strange creature, descending
without any movement of its fins, did come within reach, there also
appeared again, in the distance, the black form of the "killer" whale,
swimming far overhead. The monster changed his plans instantly. His
interest in the newcomer died out. He became intent on nothing but
keeping himself inconspicuous. The newcomer, unconscious of the terror
lying in wait so near him and of the dark form patrolling the upper
green, alighted upon the wreck and groped his way lumberingly into the
cabin, dragging those two slim antennae behind him.

IV

When Jan Laurvik, in his up-to-date and well-tested diving-suit, went
down through the green twilight of the sea, he was doing what it was his
profession to do, and he had few misgivings. He had confidence in his
equipment, in his sk