There came a sudden tug that all but broke Johnny’s grip on the man’s hand. At the same time, waving above the disturbed surface of the tank, a long, slimy arm seemed to feel for the boy on the ladder.
Then, to Johnny’s vast relief, came Dave’s voice, calling:
“Johnny! Johnny Thompson! Where are you?”
“Here! Here in the tank! Help—and hurry!” Johnny shouted, desperately.
There came the sound of running feet along the deck. At that very instant, a scaly tentacle found Johnny’s wrist and wrapped itself about the two hands, binding them together as with a band of steel.
“Wha—what’s happened?” Dave threw a flash of light on the fantastic scene. His quick eye took it all in at a glance. “Hang on, Johnny! I—I’ll be back in a jiffy!” Then he was gone.
The tremendous power of that steady pull from the tank, promised to wrench Johnny’s arm from its socket. The stranger in the pool uttered a low groan. Johnny’s mind went into a tailspin, but he hung on desperately. How would this end? Would Dave never arrive?
“Now!” came from above, and Dave was back. In one hand he held an automatic, and in the other, what appeared to be an iron rod.
“Get ready for an electric shock,” he said, quietly. “I think this will fix him.”
He thrust out the rod until it touched one arm of the octopus. Next instant, Johnny felt a powerful electric shock that brought his muscles up with a jerk. Again, and yet again came the shock. Johnny could hear the stranger’s teeth chatter. Then he saw the fellow’s other hand. It was free. At the same time the scaly thing about his wrist began to relax.