The struggle that followed was fierce in the extreme. Santenel’s catlike eyes seemed able to penetrate the gloom. Raging like a madman, he bounded to and fro, striking with the quickness of a rattlesnake. Twice his fist found Frank’s face, each time Santenel dodging back and ducking in the darkness in time to escape a counter-blow.

The launch was speeding through the water.

“Where is Inza?” Frank demanded, as he leaped in between these blows. “Tell me, you scoundrel, or I’ll choke the life out of you!”

Santenel’s laugh was almost maniacal.

“Food for fishes!” he cried. “What you will be mighty soon!”

Then the hypnotist, again ducking and dodging, renewed the fight with a vindictiveness which Merriwell had never seen equaled.

Notwithstanding that the gloom seemed to favor Santenel, Frank at length succeeded in landing a blow that knocked the hypnotist against the wall. He went against it with a thud, dropped downward as if falling in a limp heap, then straightened half up and pitched toward a door which opened to the little deck.

Before Frank could take advantage of his successful blow Santenel had drawn his thin body through this door and was scrambling out of the place.

Frank lunged and caught the man by the coat as he gained the deck. But the hypnotist slipped out of the garment, leaving it in Frank’s hands.

Merriwell sprang after him, intending to catch him and force him to tell what had become of Inza. He did not believe that Inza had fallen or been thrown overboard, in spite of Santenel’s horrible declaration that she had become “food for fishes.”