"That"s all I wanted to know," the masked man snapped. A big gun appeared in his hand. It roared once.
Pete Mills" scarred face vanished as an explosive bullet struck it squarely in the center.
The tall man whirled on others of the gunmen, his weapon steady. "Mills had ideas of taking over," he snarled. "That was his error. I am still boss."
The swing of his head had loosened the handkerchief he"d used to conceal his features. The handkerchief slipped down.
Monk and Ham looked startled. They turned to the girl for confirmation. She nodded her head slightly.
"Yes," she said bitterly. "You"re right. There is your master mind, a man you thought dead.
"That is Jerome Gadberry!"
MONK and Ham with their two companions were herded to a corner on the wharf. They were kept under the constant menace of ready guns.
Gadberry rapped sharp orders. Men from the submarine and those who had been on the island worked swiftly. Some cargo was taken from the sub, other was put in.
"We"ve got to run for it," Gadberry snapped. "We"ll take only the most valuable stuff."
Neither Monk nor Ham paid much attention. They were still dazed at news of Doc"s death. Roland Stevens appeared in a stupor. His triple chins rested on his chest; his eyes were dull.
Ham roused himself with an effort, turned to the girl.
Alice Dawn"s large eyes looked at Ham with understanding. Talk would divert his mind from tragedy.
"Gadberry, as I know now, once was connected with criminals," she said slowly. "He was the chemist for a group of rumrunners and bootleggers. Then he became respectable, and won fame as a scientist.
"Several months ago he became connected with Mr. Stevens here, and with Turner Vineland. Stevens, the actual inventor, had asked Gadberry"s and Vineland"s aid with a device he thought would end the submarine menace forever."
Stevens looked up at the sound of his name, then nodded.
"The device was taken into the Gulf of Mexico for testing," the girl went on. "Gadberry told the others to let it stay there for a time, then they would get the government interested, would obtain the use of a submarine. Actually, he had other things in mind."
"Ah," Ham said. "I"m beginning to see some light."
The girl"s head lowered. "You are right. Gadberry got word to another man, a man known as Hahln, about this device. Hahln, a spy, pa.s.sed the information along to his government, as Gadberry had known he would.
"That government was going to send a submarine to the United States, anyhow. It decided to investigate the new antisub device as well.""And got caught. That was the sea serpent," Monk put in.
"Right," Alice Dawn agreed. "Gadberry had expected that from the start. He even had a crew ready to operate the sub, headed by Pete Mills. He had this hide-away located-he knew of it from rum-smuggling days-and he deliberately waited until the men on the submarine were dead before he took Vineland and Stevens to the spot."
"But Hahln," Ham objected. "Couldn"t he do anything?"
"How?" asked the girl. "He didn"t dare go to the authorities. He tried to get Doc Savage at once. When he knew the crew on the submarine was dead, he came to Gadberry"s office, tried to kill him."
The girl paused. She looked tired and sad.
"And then-" Ham prompted.
"Gadberry did the killing. He had known Hahln was coming. He had even instructed me how to help protect him. I was a fool. Gadberry made me believe Hahln was a spy trying to steal a valuable secret for a foreign power, convinced me I should lie for him, help him in every way."
"But I still don"t see one thing," Monk objected. "How could Gadberry pa.s.s himself off as someone else?
Why would the police think Hahln"s body that of Gadberry?"
"That is something I just found out," Alice Dawn said slowly. "Gadberry did more than murder a spy. He murdered a man who once trusted him-his own half-brother."
THERE was a flurry of activity on the submarine. The cargo hatch was lowered. The sub was ready to put to sea.
"Weren"t you suspicious when Vineland was killed? When Stevens here was kidnapped?" Ham rasped.
The girl shook her head slowly. "I did not know about Vineland. And Gadberry told me to get Stevens away so that he could not talk, that even Doc Savage might be an enemy. I am sorry to say I believed him."
There was no chance for further conversation. Rough hands seized them, bound their arms behind them.
Gadberry came forward.
The tall man stood stiffly erect, the gun loaded with explosive bullets in his hand.
"This is going to give me pleasure," he announced softly. "Even though I regret that Miss Dawn must be among the victims."
"You still can"t get away with it," Ham put in harshly.
Gadberry shook his head. "I think I can, my friend," he snapped. "When warships and planes arrive, they will find little on this island to help them. You will all be gone. There will be none left to tell the tale.
"And a submarine is hard to find. There is a certain South American country I know where the millions in supplies I have, will win me an honored place."
"What happens to us?" Monk asked harshly. The homely chemist looked as belligerent as usual. Only Roland Stevens appeared to have no hope.
Jerome Gadberry rasped swift orders.The answer to Monk"s question was swift in coming.
The four were hauled forward, onto the deck of the pirate submarine. They were stretched full length upon that deck and tied there.
Gadberry had not been exaggerating when he said there would be little left on the island to tell what had happened, and that there would be none alive to talk.
The submarine would move out, would submerge slowly. The helpless captives on the deck would drown, slowly and agonizingly.
A strange grin crossed Gadberry"s features. His gunman clambered aboard the submarine, vanished beneath. Gadberry was the last to enter the conning tower.
"Good-by, my friends," he jeered softly.
The conning-tower hatch came down. The submarine got under way, moving toward the open sea.
Slowly it started to submerge.
It was then that Doc Savage appeared.
Chapter XIX. TRAITORS DIE.
THE diver who had descended from the pirate sub on Pete Mills" orders had made several errors.
His chief one had been in believing he saw the bronze man"s drowned body. Doc was there all right, but he was far from dead. He had merely wished to create that impression.
It had been apparent to Doc and Long Tom from the first that the "octopus" or "sea-serpent" device operated on the principle of magnet mines.
The "tentacles" were the long feelers of the device. Long, steel cables, held a short distance beneath the surface by floats, they were attracted by the steel of any submarine that came near, would lash out, wrap themselves about the unlucky sub.
And when the "tentacles" went into operation, they set in motion machinery contained in the "octopus"
part of the body. This machinery, held to the bottom of the sea by heavy weights, pulled the submarine down, held it fast.
At the end of three days the machinery would demagnetize the cables automatically, would release the captured sub, but by that time the crew would be dead. It also was possible, as Doc figured out, to get a copper wire to the machinery, and demagnetize it earlier.
But there was a perfect defense against this type of attack. If a submarine itself was demagnetized, it was safe. And it could be so demagnetized by running a cable about it, and running current through that cable so that it would repel, rather than attract the "tentacles."
The pirate submarine had been so equipped. This had enabled it to slip through the "tentacles." So had Doc"s sub, but he had wanted it to look as if he had been caught.
And he had succeeded.
Actually, Long Tom had turned on current for a moment, had released Doc, then had let the "tentacles"
grab hold of the submarine again.When the diver came down, Doc already had been in his sub, had donned a special diving suit. The suit was one he himself had perfected.
That suit, of special, transparent composition, enabled the bronze man to move freely. And inside, it contained sufficient supply of oxygen tablets to last for hours.
As the diver had returned to the pirate submarine, Doc Savage had followed on the ropes behind him.
He had held onto the deck, had ridden the pirate into its stronghold, then had slipped from view.
MONK howled with glee-then almost strangled as he took aboard a full mouthful of water. Ham"s features split in a wide grin.
Roland Stevens looked as if he were seeing a ghost. But Alice Dawn managed a wan smile.
The bronze man worked swiftly. A knife came to his hand. He slashed loose the ropes that held the four to the deck of the submarine.
And barely in time. The sub"s deck vanished beneath the surface.
Jerome Gadberry really wasn"t suspicious. He was merely cautious. He lifted the conning-tower hatch for one last look before fully submerging.
He saw Doc Savage.
A howl of rage came from the tall man with ramrod back. His big gun appeared, spun toward Doc.
Doc leaped forward. Without question he could have reached Gadberry in time.
Roland Stevens spoiled that. The big man slipped on the wet deck of the submarine, crashed into Doc, knocking him aside.
An instant later the gun spoke. Its explosive bullet caught Stevens in the middle of his huge paunch. That paunch seemed to disintegrate.
Doc had been knocked in the water. Monk, Ham and Alice Dawn already were swimming for sh.o.r.e.
They were keeping their heads beneath the surface.
Jerome Gadberry hesitated. For a moment he seemed undecided whether to stay and try to kill Doc, or to leave.
Then he made his decision. There was no time left to return and hunt down the bronze man"s aids as well as Doc.
The conning-tower hatch slammed shut. The submarine vanished beneath the surface.
An instant later, Doc appeared on the other side of the sub. There was a small gla.s.s bulb in his hand.
Had that bulb been thrown inside the conning tower, Gadberry and those with him would have been overcome, could have been taken captive.
Now it was too late.
Doc"s gold-flecked eyes flashed strangely. He cast a quick glance toward the sea, toward the spot where the island channel entered the Atlantic.
Monk and Ham pounded the bronze man on the back, telling him over and over how glad they were tosee him. Alice Dawn, her flaming crimson hair returned to its original darkness by sea water, smiled shyly.
"I"m only sorry those killers are getting away, daggonit!" Monk bellowed finally. "I"d like to have gotten in one good smack at that guy myself."
Doc Savage said nothing for the moment. Instead, he turned, looked again toward the spot where the island channel entered the sea.
The bronze man"s gold-flecked eyes appeared slightly puzzled.
"IT was too bad, though," Ham put in, "that Stevens had to get his right at the last. He helped us a lot."
Doc nodded, but did not speak. The bronze man knew, what the others did not, that Stevens had stood by while seamen, still alive on the captured submarine, had been shot to death by the pirates.
Undoubtedly Stevens had been afraid. He had not been a criminal at heart. But he could have spoken up, could have told the authorities what had happened, might have saved the lives of scores of others.
"You know what it is all about, "sea serpent" and all?" Monk demanded.
Doc nodded.
"You two took underwater pictures near where the "sea serpent" was seized," he explained, "but you found nothing because you were not at the right spot. I found a map in Gadberry"s office which helped me, and discovered huge anchors beneath the surface. From that, it was simple to deduce the rest."
Neither Monk nor Ham thought it was simple, but they said nothing.
"But why were the government men watching you in New York?" Ham asked curiously.
Doc turned toward Alice Dawn. "I think this young lady can explain," he said quietly.