"Got him!" the vicious fellow chortled. "Easy money, the twenty grand Kar is payin’ me for this!"

The murderous pilot did not dream Doc Savage could have escaped. He had no comprehension of Doc’s physical powers.

But he had been warned to make absolutely certain. He circled continuously above the lagoon, eyes roving like a vulture’s.

Under an overhanging bush, a full hundred yards from the bridge, Doc’s bronze head broke water. He came up so smoothly that there was no splash.

The killer pilot of the seaplane did not see Doc glide into the shrubbery, although he was staring mightily.

An onlooker would have remarked a striking thing about Doc as he came out of the water. Doc’s straight bronze hair showed no traces of moisture. It was disarrayed. It seemed to shed water like the proverbial duck’s back. Nor did moisture cling to Doc’s fine-textured bronze skin.

This was but another of the strange things about this unusual metallic giant of a man.

Near by stood a Park policeman. The officer was goggling at the spiraling plane. He had seen the baseball-sized bomb drop. He had witnessed the upheaval of queer gray smoke.

The cop was trying to think what to do about it! Nothing like this had ever happened before.

The officer fingered the grip of his revolver. Then the revolver was spirited from under his fingers. He had heard no one come near. Wildly, he turned.

Even as he spun, the revolver banged itself empty of cartridges. The shots came so rapidly as to be a single thunderous whurr-r-ram!

The circling seaplane gave a wild lurch. A wing sank. It nearly crashed. The pilot was wounded. But he fought the ship to an even keel. The plane scudded away like a shot-splattered duck.

The policeman suddenly found his warm, smoking gun back in his hand. He had a dizzy vision of a great bronze form in dripping clothes. He even noted the bronze man’s face and hair seemed perfectly dry, although his clothing was saturated.

Then the giant was gone into the shrubbery. And there was no sound to show from whence he had come, or where he had betaken himself.

The cop looked into the bushes and saw nobody. He gulped a time or two and wiped sweat off his brow.

"Goshamighty!" he managed to croak at last.

AT the Fifth Avenue side of Central Park, Doc Savage got into a taxicab. It hurried him southward. Before a towering, gleaming spike of brick and steel, the machine let him out. Streets here were walled by buildings so tall the sunlight only reached the sidewalks at high noon.

An elevator raced Doc up to the eighty-sixth floor. He entered a sumptuously furnished reception room. No one was there. He went to the next room. This was a library, a chamber which contained thousands of the finest technical tomes.

Into another and much larger room, Doc went. This was the laboratory. Marble and glass-topped work tables were everywhere. Scores of huge steel-and-glass cases held chemicals, rare metals, test tubes, siphons, mortars, retorts, tubing and apparatus of which only Doc knew the use. No one was there.

This laboratory was exceeded for completeness by only one on earth — the one which Jerome Coffern had told his fellow chemists that Doc must visit to conduct his great experiments uninterrupted. Jerome Coffern’s guess had been right.

Doc had another laboratory, vaster even than this. It was at the spot he called his "Fortress of Solitude." This was built upon a rocky island far within the arctic circle. No one but Doc knew its location. And when he was there, no word from the outside world could ever reach him. It was to his Fortress of Solitude that Doc retired periodically to study and experiment and increase his fabulous store of knowledge.

Convinced none of his five friends had as yet arrived, Doc returned to the reception room. He stripped and donned dry clothes which he got from a cleverly concealed locker.

Doc’s frame, stripped, was an amazing thing. He had the muscles of an Atlas. They were not knotty, but more like bundled piano wire lacquered a deep bronze color. The strength and symmetry of that great form was such as to stun an onlooker.

Suddenly there came an interruption.

Wham!

The report was loud. With a rending of wood, the thick panel of the outer door caved inward, propelled by an enormous fist. That fist was composed of an ample gallon of knuckles. They looked like solid, rusty iron. And it would have taken a very big and violent mule to do as much damage to that door as they had done.

The fist withdrew.

A man now opened what was left of the door and came in. He was at least six feet four in height, and would weigh two fifty. The man resembled an elephant, with his sloping, gristle-heaped shoulders.

He had a severe, puritanical face. His eyes were dark, somber and forbidding. His mouth was thin and grim and pinched together as though he disapproved of something.

This was Colonel John Renwick. Every one called "Renny." He was honored throughout the world for his accomplishments as a civil engineer.

Renny looked like he was coming to a funeral. Actually, he was literally rolling in joy. His popping out the panel of the door showed that. It was a trick Renny did when he felt good. And the better he felt, the more sour he looked.

"Where’s this trouble you was tellin’ Monk about?" he asked Doc.

Doc Savage chuckled. "It’ll keep until the others get here. I’ll tell you all together."

SOON two men could be heard haranguing each other loudly in the corridor.

"You can’t tell me nothing about electronic refraction, you skinny galoot!" shouted a belligerent voice. "Electricity is my business!"

"I don’t give a snap if it is!" retorted another voice. "I’m telling you what I read about electronic refraction. I know what I read, and it was in an article you wrote. You made a mistake — "

There was a loud slamming noise. A man came flying into the room, propelled by a vigorous toe.

This man was tall and gaunt, with a half-starved look. His shoulders were like a clothes hanger under his coat.

He was William Harper Littlejohn. The year before, he had won a coveted international medal for his work in archaeology.

"What’s the trouble now, Johnny?" Doc inquired.

Johnny got up from the floor, laughing.

"Long Tom wrote an article for a technical magazine and he made a mistake any ten-year-old kid could catch," Johnny chuckled. "He hasn’t seen the article since it got in print, and he won’t believe me."

Snorting loudly, an undersized, slender man came in from the corridor. He had a complexion that was none too healthy. His hair was pale, his eyes a faded blue. He looked like a physical weakling. He wasn’t, though. It had taken a lusty kick to propel Johnny inside.

The undersized man was Major Thomas J. Roberts on the official records, but Long Tom to everybody else. He had done electrical experiments with Steinmetz and Edison. He was a wizard with the juice.

"Where’s Ham and Monk?" Long Tom asked. "And where’s this trouble? I’m gonna tear an arm off Johnny if I don’t get some excitement pretty quick."

"Here comes Ham," Doc offered.

Brigadier General Theodore Marley Brooks now appeared. He was a waspish, swift-moving, slender man. Of all the lawyers Harvard had sent forth from its legal department, it was most proud of Ham. He was an amazingly quick-witted man.

Ham’s dress was the ultra in sartorial perfection. Not that he was flashily clad, for he had too good taste for that. But he had certainly given his attire a lot of attention.

Ham carried a black, severe-looking cane with a gold band. This was in reality a sword cane, a blade of keenest Damascus steel sheathed within the black metal tube.

Ham also was eager for action.