"We'll soon see," Doc replied. "I have taken no particular pains to keep our coming secret. The Gray Spider might have heard me getting weather reports over the radio. He could use a directional radio loop and locate us."
Doc's ship held its course. The other craft drew closer. It was a high-wing monoplane, with a tube of a fuselage. As commercial jobs went, it was fast.
Suddenly the ship zoomed upward, as though to let Doc pass below.
"I guess it's just some plane making a night flight—"
Ham never completed his statement.
With an abrupt dive, the other plane flashed in front of Doc's craft. At the same instant it released a tremendous gush of vile greenish vapor. The stuff spread rapidly.
"Poison gas!" bellowed the quick-thinking Ham.
Doc's speed plane could not swerve aside in time to avoid hitting the gas cloud. It had been released almost against the trio of flashing propellers.
Comely Edna Danielsen went white, and spread her hands over her face. Big Eric, a quick thinker himself, sucked in air to fill his lungs before the poisonous fumes came. The prisoner sat still, as unconcerned as a machine—for he couldn't think enough to realize there was danger.
The plane popped into the gas cloud. It came out. One minute passed. Two. The gas cloud was left nearly five miles behind.
Nothing had happened.
Doc banked the plane swiftly. He flung it for the craft which had tried to gas them.
"Hey!" puffed Big Eric, unable to hold his breath longer. "Ain't that gas gonna—"
"The plane cabin is airtight," Doc Savage pointed out. "Haven't you noticed you have experienced no difficulty in breathing during the flight, although we flew above twenty thousand feet much of the time? That was because the cabin is air-conditioned—furnished with oxygen stored in a special supply tank."
The gas plane was striving frantically for altitude, after the manner of combat craft. But it was like a clumsy buzzard fleeing from a speedy hawk. Doc's great racer came alongside. He saw the other pilot was wearing radio earphones.
"Land—immediately!" Doc's powerful voice boomed into his own radio transmitter.
The excited actions of the other flier showed he was tuned in on Doc's wave length. He had located Doc's plane by radio!
INSTEAD of landing, the pilot banked swiftly. A machine gun, synchronized to shoot through his propeller, mouthed nasty red tongues.
The burst stopped short—for Doc's sky streak had flipped far to one side with a lightninglike maneuver.
Then the entire forward edge of the wing of Doc's ship seemed suddenly outlined in terrible little red electric bulbs. An awesome vibration swept the craft. For there was no less than ten Browning guns installed in the wings of the plane!
The other craft, able to fly but a little more than half as fast, and with only one rapid-firer, was helpless before this ultramodern sky terror. The Gray Spider pilot knew he had caught a Tartar. He shrieked and put his hands over his face as lead popped and tore and screamed about his ears.
The metal storm ceased.
Fearfully, the pilot peered up. He jumped as a commanding voice crashed in his radio ear phones.
"You have one more chance to land!"
Such a fearsome quality did that great voice hold, even though distorted by the metal telephone diaphragms, that the vicious pilot put the nose of his plane down as though his very life depended on reaching the ground in less than nothing flat.
The fellow was such a nervous wreck that he washed out his plane in landing. Coming down too heavy, the landing gear was wiped off, the propeller beat itself into a ravel of metal, and both wings were knocked askew.
Unhurt, the pilot bounded out. He looked up. Doc's plane was flashing in like a great bat. The would-be killer ran. The nearest brush was but a few rods distant.
But long before he reached it, a giant of bronze overhauled him. Arms that could be compared only to steel trapped him. He thought for an instant that the awful strength of the grip was going to crush his life away.
That did not happen. He was carried to the speed plane. He tried to struggle, but the sinewy bronze hands tightened and hurt him so he could only tremble and scream.
A small needle gouged the man, and suddenly the man ceased all action. He was the second victim to undergo an injection of Doc's special serum.
"Get in the plane!" came Doc's commanding voice.
The pilot got in the plane. He couldn't think of anything else to do.
Doc Savage entered also. In a moment, the remarkable air vehicle took off.
SOON they circled a New Orleans airport. Concealed lids on the undersides of the wings slid back, revealing the lenses of powerful landing lights. These sprayed luminance. The ship landed.
Big Eric looked at his watch.
"Golly!" he gasped his pet expression. "It ain't much past midnight!"
Then Big Eric's eyes popped as a black limousine purred out on the field and the driver threw open the door and said: "The car you ordered to meet you, sir!"
"I used the radio in the plane to summon the machine," Doc told the surprised lumberman.
"Things have got a habit of happening smooth and fast around Doc," grinned Ham, twiddling his indispensable sword cane.
Big Eric was a man who worked swiftly. He wouldn't have been a multimillionaire otherwise. But the speed with which Doc Savage was doing things had him a little dazed.
Accompanying the mighty bronze man was something like going around in the middle of a whirlwind. It was hard to keep track of things. Two of the Gray Spider's men captured, and two attempts on their own lives thwarted. A hop from New York to New Orleans! And the night was young!
The limousine rushed them to Big Eric's palatial home in a swanky district.
Doc carried his two prisoners inside.
"Sit down!" he told them.
They sat meekly in chairs. It was an awesome thing to see such vicious devils obey as though they were machines actuated by jabbing a button.
"I shall leave for a while," Doc told his three companions. "It is essential that I do certain work."
He did not explain that this work was to leave a message in the invisible ink which could only be brought out by ultraviolet rays. This message would be written on the front door of the Danielsen & Haas lumber concern's office. Doc knew that his other four men, Monk, Renny, Long Tom, and Johnny, might arrive before the night was over. They were no slouches themselves, when it came to fast moving.
Doc kept silent about the message for the simple reason that the two prisoners, although unable to think, would remember everything that had happened to them, once they awakened from their strange trance. He did not want them to overhear.
Doc took his departure. The driver of the limousine was astounded when his giant bronze passenger rode outside the running board, although the tonneau was empty. But Doc Savage habitually did that when danger was aprowl. He liked to see what went on about him.
From the door, Big Eric watched Doc go.
"A remarkable man," he declared. "You know, I already feel as though I had nothing more to fear from the Gray Spider!"
Hardly were these words off his lips, when he gave a sharp start. A dazed expression came into his eyes. He fumbled at his chest.
He fell with a loud crash to the floor. His massive frame lay limply.
Beautiful Edna Danielsen shrieked. She sprang toward her father. She, too, started violently. She seemed bewildered. Then she collapsed.
Ham whirled. His sword cane was unsheathed. But he saw no enemy. He leaped wildly for a door, to escape. Then he twitched, became vacant of expression, and himself tumbled down alongside the others.
The three forms were motionless.
Big Eric had spoken too soon. For the hand of the Gray Spider had stricken down every one in the room!
Chapter IV. TWO DEAD MEN
AN ominous silence gripped the room where the three limp, unmoving forms lay. The slow tick-tock of a wooden clock in another part of the mansion was a sound like the bony footsteps of death. The motor of an electric refrigerator ran softly back in the kitchen regions.
From the Mississippi River in the distance came the forlorn toot of a packet boat. A radio played through an open window in the more immediate neighborhood. There was a party where the radio played. Glasses clinked. Giddy laughter cackled.
A voice said: "Me guess coast ees clear!"
Two queer-looking men stepped out of a closet.
They were undersized. Their skins had an unusual yellowish-brown color. Their features were pinched.