The light ahead of us winked like a will-o’-the-wisp as intervening branches of coral, the edge of a mud-bank, or perhaps the body of some living creature, momentarily blotted it out. We were close to the bottom now. Along here it was a rolling, but fairly even bank of ooze, with grotesque squat plants growing in it.
The light could not have been more than a few hundred feet in advance of us; in its glow we could sometimes see the outlines of the human figure carrying it. We did not dare speak aloud now; we swam with that speed and silence which only one who lives in the water can attain.
Presently the light dipped downward and vanished. We saw that this figure we were following had entered a black cave-mouth—an opening which ran diagonally down into a slimy bank of mud. And we saw, too,
