The girl blushed. "I . . . I am afraid I can," she admitted. "You see, I took what Mr. Gadberry said seriously. I thought you really might be an enemy, and that I was fighting for my country. I must have made my story convincing."
"You"ve explained how the "sea serpent" worked," Monk puzzled, "but remember Stevens said if a sub had it, it was a protection. How about that?"
"It could stop any depth bomb," Doc said briefly. "One of the "tentacles" would grab the bomb, and by regulating the machinery in the device, the bomb would be held too high to explode until such time as was safe."
The bronze man glanced again toward the mouth of the island channel. This time there was no question about his look. It was frankly puzzled.
A seaplane roared by overhead. Seconds later two more flashed by. They circled the island, looking for signs of life before landing.
A long white line appeared in the water of the channel. A conning tower broke the surface. A minute later and Renny, Long Tom and Johnny, whooping joyfully, joined the group on the sh.o.r.e.
WARSHIPS soon joined the seaplanes. By nightfall the water around the island resembled a navy base.
There were fighting craft from many nations.Doc, his aids and Alice Dawn were guests aboard the American flagship.
Already explanations had been made, but they were forced to tell their story many times for admiring officers.
And already their story had been radioed to the newspapers. Doc Savage no longer was a hunted criminal. Once again he was the world"s hero.
Doc"s popularity increased when it became known that he would not accept the million offered for capture of the pirate craft that had terrorized the entire seaboard.
That million, the newspapers announced, would go to the families of seamen who had been killed by the terror.
The admiral took Doc Savage to his private quarters.
"You say that you and Major Roberts improved upon Stevens" original invention?" he asked.
The bronze man nodded. "The plans will be given the navy department," he promised. "You see, protection from a magnetic device of that kind is effective only if it succeeds in repelling either a positive or a negative attraction.
"The tentacles Long Tom devised offset that point. One tentacle would be pulled to a negative pole, the other to a positive. So no matter what type of current was used in the protective device, one tentacle or the other would catch hold."
The admiral nodded. "And there is no chance of recovering the body of this man Gadberry?"
The bronze man shook his head. "None," he said. "I confirmed the story told me by Renny and Johnny.
"The sub-catching device that Long Tom perfected was set just outside the island channel. Johnny and Renny then retired to watch. The tentacles caught the pirate submarine successfully, and one fouled an open ballast vent. The submarine filled and went to the bottom.
"That had been expected. But there is a deep shoulder just off this island. The water goes down for thousands of feet. No submarine can stand that. The submarine burst open. All aboard were killed."
"And by their own device," the admiral said thoughtfully.
THE END.