"Outside!" Doc's powerful voice crashed. "Stand on the sill!"

Big Eric and Edna hastily scrambled out. Ham followed. The window sill was hardly six inches wide. They were forced to grasp every handhold that offered to their finger tips.

"No use!" Big Eric wailed. "The infernal gas will seep around the window edges and get us! These sashes don't fit tight! I've often felt a draft when they're closed!"

It was Doc Savage's keen brain that solved the problem.

A small pot of ordinary white paste stood on Big Eric's shabby desk. Doc scooped this up. He joined the others outside on the window sill. He closed the window.

With quick strokes, Doc strung the gummy white paste around the window, effectively sealing all cracks.

"That's what I call quick work!" Big Eric said admiringly. "But why couldn't we have dashed through the gas cloud to the door?"

"The stuff is not only deadly if inhaled, but fatal if it touches the skin, unless I am mistaken," Doc explained. "I believe it is closely akin to the terrible mustard gas used in the World War."

Doc sidled swiftly to one end of the window sill.

The next window was half a dozen feet distant. The wall between was every bit as smooth as glass.

But Doc Savage, employing the springy tendons of his legs, and the balancing effect of his strong arms, leaped side-wise from the window sill. It seemed an impossible feat to accomplish without falling outward from the sheer building.

His great bronze frame appeared to skid a rising arc along the wall. He reached the next window. His powerful fingers grasped and held.

He was safe!

It had happened before the others could as much as emit a gasp of amazement.

"Stay where you are!" Doc commanded them.

A FRECKLED stenographer strangled on the gum she was chewing as the big bronze man appeared like magic in the window beside her desk. She was still coughing when Doc crossed the room and entered the corridor. She had received the shock of her gum-chewing career.

Doc watched the building entrance several minutes. He saw no one leave in a suspicious manner.

Returning upstairs, he noted that old Silas Bunnywell, the bookkeeper, occupied a tiny cubicle from the door of which the entrance of Horace Haas's office could be seen. Old Bunnywell was stooped over his ledgers.

"Have you noticed Horace Haas leave his office recently?" Doc inquired.

The old man took off his glasses and rubbed his reddened eyes. "No, sir. I'm quite sure I haven't. Mr. Haas must be in his office now. Only a few minutes ago, I saw two men hand a bag through his door."

"Describe them!" Doc commanded.

Elderly Silas Bunnywell gave an accurate description of Lefty and Bugs.

Doc recognized the pair from what Big Eric had told him of them.

"And Horace Haas is in his office now?" Doc said grimly.

"I am not sure. But he must have been there a few minutes ago. I am not able to observe all who enter, because of my work."

Doc swung to the door of Haas's office. He opened it. He was cautious, not knowing what form of death might lurk within for him. But he need not have been careful.

The office was empty, but Doc saw the gas contrivance.

He turned off the petcock on the tank of gas in the hand bag. Then he got a rope, went to the roof, and rescued Big Eric, Edna, and Ham from the window sill.

They held a serious council in Haas's office.

"It looks bad for friend Horace!" Ham said, tight-lipped.

"You mean you think Horace Haas turned that gas on us?" Big Eric muttered.

"What do youthink?"

"I don't know," Big Eric replied, a long hesitation between each word. "I hate to think he'd do such a thing. But there's no reason why he should go out."

At this juncture, Horace Haas came into the room. His step was not as jaunty as usual. He looked like a fat, overfed pup somebody had just kicked. He gave a distinct start at sight of Doc and the others.

"I—er—hello," he said uncertainly.

Big Eric got to the point without delay.

"Where in thunder have you been?" he roared.

Horace Haas reddened angrily. "Since when was I tied to your apron strings? None of your business—where I've been!"

"It might interest you, wise guy," Ham put in, "to know that an attempt was just made on our lives from your office. And, to be very frank, you are under suspicion!"

THIS blunt declaration had a marked effect on Horace Haas. He reddened even more—then suddenly went quite pallid. He fumbled for a chair with a jeweled hand and sat down heavily.

Doc Savage watched the man. Either Horace Haas was a finished actor, or he was genuinely shocked at the accusation.

"I—er—suppose I had better tell where I was." Horace Haas pulled a large silk handkerchief from his pocket and dabbed his forehead. The piece of silk was brightly colored.

"I received a telephone call from a—er—young lady," Haas began.

"A chorus stepper?" rumbled Big Eric.

Horace Haas flinched. "Ah—yes, a young lady of the chorus. At least, that is who she said she was. She asked me to meet her at a soda fountain near here. So I went—"

"An old goat of your age!" Big Eric snorted. "I oughta get up and kick the seat of your pants!"

"—but I didn't find the young lady!" Horace Haas finished desperately. "She did not appear. I waited some time, decided I was being stood up, and came back."

Big Eric rumbled a noisy laugh. "Somebody played you for a sap to get you out of your office so an attempt could be made on our lives!" He whirled to Doc. "Don't you think that was it?"

Doc had formed no definite opinion. He had no proof against Horace Haas—he had no real proof that he was innocent, either. He gave a noncommital answer.

"Possibly."

Swinging over to the telephone, Doc called the number of the telegraph company branch office from which he had engaged his messenger. He was merely checking up on whether the dictaphone records had been delivered to his fellow scrappers.

He received the bad news.

"What?" he demanded. "The messenger was waylaid and robbed en route?"

Hanging up, Doc let his golden eyes range over his companions.

"It seems," he said slowly, "that the Gray Spider is setting out to carry the warfare to us."

"The boys may be in danger!" Ham clipped.

Doc nodded. "Exactly. You stay here, Ham. Take every precaution to guard against the Gray Spider. I'm going to see if our four brothers are in any kind of a mess!"

He left the building swiftly.

THE hotel to which Doc Savage had directed his four men was the Antelope. It was neither the largest nor most luxurious in New Orleans. Conservative business men and drummers patronized it for the most part.

Doc parked his roadster a block from the hotel, and on the opposite side of the street. He mingled with the pedestrians. These turned, practically without exception, to stare at the amazing bronze man. He was far more striking in appearance than the pictures that accompany the strong-man advertisements in magazines. The fact that Doc wore no hat added to his prominence.

Before the Antelope Hotel stood a vanlike delivery truck. This was marked with the name of a prominent baking concern.

On the truck seat sat the burly, hard-featured crook of a lumber detective, Lefty.