"What's this?" questioned the electrical wizard.
"All you need to make a supersensitive microphonic 'ear'," Doc explained. "Set it up in the center of our fortress. When night comes, the voodoo men will no doubt try to creep up close enough to hurl bombs into our dugouts. But with your apparatus, you can hear them."
Long Tom nodded, then fell to examining his apparatus. He became elated. With this stuff, he could make a microphonic listening and amplifying device that would pick up the buzz of a fly at the distance of half a mile. Scant chance would skulkers stand of creeping upon them now.
Doc Savage busied himself with poor, half-witted Sill Boontown. A kit which he had brought from the plane proved to be a compact set of surgical instruments. It even included hypodermic needles for administering a form of local anaesthetic, a pain-deadener which affected only the part being worked upon.
"He's gonna operate on the kid!" Monk grunted.
"Two bits says the kid is normal as you or me when Doc finishes!" Ham offered.
"You would want to bet on a sure thing!" Monk snorted.
Both Ham and Monk were fully aware of Doc's magical skill in surgery. For it was at this, above all else, that the mighty bronze man excelled.
Surgery had been Doc's first training in life. It had been his most intensive. Although his ability at other lines of endeavor might seem uncanny, his accomplishments with surgery and medicine were far more marvelous.
It was an interested group that watched the delicate operation. Sinewy bronze fingers, steady as steel on a foundation of bedrock, laid back the scalp. A small aperture was opened in the skull.
As Doc had expected, a fragment of bone was pressing upon the brain, paralyzing certain of its functions. The blow on the head two years before had caused the trouble.
The bone fragment was removed. Swiftly, Doc completed the delicate operation. With catgut, which would dissolve of itself about the time the wound was healed, he stitched the scalp in place.
The effects of the anaesthetic wore off.
"How do you feel, sonny?" Doc inquired.
"I got one whopper of de headache!" replied the boy.
His tone showed that he was perfectly sane!
It was magic! Monk, Ham, Renny, Long Tom, Johnnythey all exchanged strange glances. Accustomed as they were to the marvelous things Doc Savage did, and knowing that such a brain operation was not unique in surgery, they were nevertheless awed.
Lost from the outside world, beseiged here in the steaming, festering swamp, volleys of machine-gun slugs storming over them every minute or so, the feat could not but impress them as uncanny.
They scattered to their gun emplacements, wriggling through the shallow trenches they had dug.
Time now dragged. Long Tom finished his microphonic listening device. It was something like the apparatus used by the defenders of London during the Great War to listen for Zeppelins and planesalthough far more perfected.
It was well after noon when Doc Savage caught sight of Buck Boontown. The man was directing the seige.
Doc signaled Buck Boontown. It was his intention to inform the swamp man that his son would join him shortly. There was no longer necessity for keeping Sill Boontown here. The lad would not bungle into danger, now that his mental powers were normal. And even had the boy wanted to assist the beseiged man, Doc would not have permitted the lad to oppose his father.
Buck Boontown was suspicious. He thought Doc's wig-wagging was a trick. So he blazed away with a machine gun. His accurate fire caused Doc to duck swiftly.
BUCK BOONTOWN chortled gleefully at the results of his rapid-fire blast.
"Bien!
MeI almo' got heem that time!"
He watched the molelike mounds and tiny ridges of dirt the defenders of the hill had thrown up. His blasphemous pleadings to his hideous voodoo deity for another shot went unanswered.
Soon one of the other swamp men wriggled up with a message.
"Gray Spider ees want yo'!" he told Buck Boontown. "He's send message. Yo' ees to go to Castle of the Moccasin!"
"Oui!"
smirked Buck Boontown. "MeI go plantee queeck."
The swamp man was flattered. Although by far the most intelligent of the debased clan of humans who had resided in this great morass so many generations they had reverted to a state of near savagery, Buck Boontown was, nevertheless, far from a smart man.
He fawned like a big dog under the attentions of the Gray Spider. Sacrй!Now there was a man for you! Or so Buck Boontown thought. The money that the Gray Spider paid his swamp men minions was not a minor inducement, either. A city gunman would have sneered at the smallness of the sums, but to these swamp dwellers, each pittance was a little fortune.
As he plowed through the tangled morass, Buck Boontown treated himself to flights of imagination. He was saving his money. Already he had quite a sum hidden in a fruit jar in the swamp. He would hoard more. He might even get enough to go to the great and marvelous city of New Orleans and spend the rest of his days. He had heard of the wonders of that metropolis, but had never been there. Indeed, he had never been out of this great swamp in his lifetime.
And the swamp was but a few hours' drive by speedy car from New Orleans!
Mile after mile, Buck Boontown covered. He kept a straight course, weaving aside only for pools and slime which he could not leap.
He was entering the most remote section of the swamp. Even the folk who lived in the great morass seldom came here. The region was forbidden to all but the inner circle of the Cult of the Moccasin. It held the Castle of the Moccasinthe headquarters of the king of the voodoo cult. The lair of the Gray Spider!
Buck Boontown climbed a cypress to make sure of his bearings.
Not a mile distant lay the Castle of the Moccasin!
NO doubt airplane pilots flying over the vast swamp and bayou district had noted the peculiar knot of trees and shrubs projecting over the surrounding territory. Probably they mistook it for a tiny clump of very tall trees.
Should they have chanced to fly low, they would have seen that these trees, strangely enough, were growing out of a great, boxlike knob which was covered completely by vines.
It had never occurred to any one that the knob was in reality a huge stone building, the roof and walls of which were cunningly camouflaged with growing vegetation.
Buck Boontown neared the strange, concealed castle of a structure.
He was challenged by a heavily armed guard, and permitted to pass. Soon he met a second guard.
It was well nigh impenetrable to the casual wayfarer, this Castle of the Moccasin. Years had been spent in its building. Labor had been furnished by the members of the voodoo cult.
The Gray Spider's campaign of wholesale looting of the great lumber companies of the South was no snap-of-the-finger scheme. It had been years in the conceiving and preparation.
Buck Boontown was admitted to the Castle of the Moccasin through a secret door.
The passage into which he came was stone-walled. Electric bulbs lighted the way. The air inside, contrasting greatly with the malodorous and steaming vapor of the swamp, was clean and pure. Buck Boontown knew nothing of such things as air-conditioning machines, so he attributed the sweetness of the atmosphere to some magic about the presence of the Gray Spider.
He entered a large room. The color scheme looked like it had been conceived by a futuristic artist who had gone crazy among his paint pots. Streaks and spots and daubs of green, red, blue, yellow, white, aluminum, goldit all made neither sense nor beauty. Concealed colored lights dancing off and on added to the garish effect.
The whole thing was deliberately conceived to impress the near-barbaric minds of the swamp dwellers who worshiped the heathen deities of voodoo.
In the center sat a throne of goldgold paint on a wooden foundation, although Buck Boontown didn't know it. To him, the throne alone represented limitless wealth.