The wall of rock to which the enemy submarine had first been charging had become visible, soaring vastly from the gloom of the sea-floor. And the monster was towing them straight into a dark, jagged cleft at its base.

"It's a cavern!" Keith breathed. "A split in the rock—the lair of that devil. And we're being dragged into it!"

CHAPTER III

Sacrifice

t that moment Keith Wells knew fear. Each second they were being hauled closer to the monster's dim lair. It lay there, dark, mysterious, fingered by gently swaying, clammy kelp. A hushed solitude seemed to reign over it, aweing all undersea life from the vicinity.... Wells turned his head to meet Bowman's eyes, and read in them a silent question.

What now?

He groaned in the agony of his mind. In a few minutes, all would be over. Once the NX-1 was dragged into that dark cavern there'd be no chance of escaping to warn the world above, of saving the submarine. What now? The question brought beads of sweat to his tormented brow. He, Keith Wells, standing impotently by while his ship, the pride of the service, was hauled inch by inch to some strange doom!

Racked by these thoughts, he murmured tortured, jerky phrases, unconscious he was giving voice to the things that flogged his brain.

"What can I do? I've got to save my ship—I've got to get back to break the news—I've got to tell the world! But how? How—" His expression changed suddenly. "That's it! That hawser arm between us must be broken!"