On we swept, just above the sea-bottom. Occasionally giant crabs would scuttle away from us, alarmed by our swift movement. To the sides, lights sometimes showed—the lighted heads of monsters. But none came near us. A thing all spines drifted past; but it did not molest us. A giant clam, larger far than any one of us, was lying on the sea-bottom in our path. It opened its shells as though hungrily to suck us in, but we avoided it. We came at last to the side wall of the black void of water—the wall alongside of which we had descended. Up there, a few thousand feet, lay the entrance to the Marinoid domain. If we could get into that entrance—into the coral forest before the black fishes caught us. . . . We swam upward, along the line of wall, a few hundred feet off. Directly beneath us now, following every twist of our trail, the pursuing fishes were yelping. They were much closer. And Nona was tiring! It was the longest, most sustained fast swimming she or I had ever attempted. Atar and Caan were drawing away from us. They did not realize it, and I did not call to them. Perhaps, if we two gave out, they could go on and save themselves. Then Caan looked back. They slackened their pace and we caught up with them. “Go—on,” I panted. But they would not go faster than we could go. And we all knew that very soon now we would be caught. We were perhaps two thirds the way up the wall when suddenly Caan and Atar swung sharply out to one side. Nona and I followed, as one fish follows the turns and twists of another. I looked to see what was wrong. Overhead, directly in our former path, loomed the black, unlighted bulk of a giant monster, huge and fearsome beyond anything we had ever before encountered! CHAPTER XXIII We had no time to decide what we should do. The monster saw us. Beneath us—almost in sight now—the black fishes were mounting. And further below them—dim and muffled in the distance—we heard Og’s voice shouting a shrill command to urge them on. We darted out sidewise, away from the wall. Atar was leading, and single-file, we others followed. Then Atar turned suddenly and doubled back upon himself. Strung out in a line, we turned with him. Making straight for the jagged cliff-face, we passed close under the monster, between it and the mounting black fishes. The monster was slow, ponderous in its movements. It was coming down, and as we darted under it I stared up and saw it plainly. A gigantic black thing. A spherical head, twenty feet broad; a thick, elongated body—a hundred feet or more in length. There were no fins, and no tail. The head had two great protruding eyes, gleaming green, and beneath them a circular mouth—a mouth which even undistended was large enough to suck in our bodies. And around the head, fastened to it—framing the face—were a dozen arms! They were waving tentacles with a sucker disk at the end of some, and a hook at the end of others.