The air-hose seemed to be clear, but Jimmie was afraid that the flounderings of the serpent might break it. The horror was certain to do some thrashing about when he felt the keen edge of the steel.
The only way was to strike some vital spot. That would end the combat at once. The serpent's head lowered with the boy, as if he had great curiosity to find out exactly what sort of a being it was that had invaded his kingdom.
The boy was cheered by the thought that the submarine had stopped, although he did not realize at the time that the signal had been given by the action of his enemy. If the boat had continued on her course, the air-hose and the lifting line must both have been broken in a short time, as the boy's progress was stopped by the great weight of his terrifying foe. Then the end would have come instantly.
The coil about the leg was drawing tighter now, and the boy was in considerable pain. Also the coils were ascending as the head of the sea monster swung around.
It was not only the pain and the deadly danger that brought a momentary shiver to the boy. It was the fact that the repulsive body of the serpent was winding closer and closer about him.
He seemed to feel the slimy skin of the deep sea terror slipping through his waterproof suit, although his common sense told him that such could not be the case. He even thought he scented the sickening odor which he had now and then experienced in the Central Park Zoo. He knew, too, that this was purely imaginary, but the horror of a nightmare was on him, and for only an instant he lost his nerve.
Once more the head swung around and the boy presented his weapon and struck with all his might. The needle-like point entered the throat of the serpent and passed through just at the back of the long, spotted head.
There was a great switching in the water for an instant, and then the coils loosened. The blow, as Jimmie afterwards discovered, had broken the spinal cord.
While not yet dead, the serpent was incapable of moving the lower part of his body. With a sense of loathing he pulled at the coils until he was clear of them.
The water where he stood was now taking on a faint reddish hue, and Jimmie hastened away. At first, weakened and shaken as he was by the disgusting encounter, he determined to return to the submarine, then the thought of what his chums would say to him if he gave up caused him to proceed in the direction of the Shark.