“Then,” said Brevard, slowly, “then the world had better die than survive under the abominable slavery now impending.  Already the pipe-lines have been laid to Buffalo, Cleveland, Albany and Scranton.  Already they’re under way to New York City itself, and to Cincinnati.  Already other plants have been projected for Chicago, Denver, San Francisco and New Orleans, to say nothing of half a dozen in the Old World.  At this present moment, as we all sit here in this quiet room on this remote mountain-slope, the world’s air is being cornered!  All the atmospheric nitrogen is planned for, by Flint and Waldron, to pass under their control—­and with it, every crop that grows.  All the oxygen will follow.  They’re already having their domestic-service apparatus manufactured—­their cold-pipe radiators, meters, evaporators and respirators.  I tell you, comrades, this thing is close upon us, not as a theory, now, but as a terrible, an inconceivably ghastly reality!

“Even as we talk this thing over, those devils in human form are at work impoverishing the atmosphere, the very basis of all life.  My oxymeter, today, showed a diminution of .047 per cent. in the amount of free oxygen in the air right on this mountain.  And their plant is hardly running yet!  Wait till they get it under full swing—­wait till their pipe-lines and tanks and instruments and all their vast, infernal apparatus of exploitation and enslavement are in operation!  Even in a week from now, or less, by the time you issue the call, Gabriel, you may see wretches gasping in vain for breath, in some dark alley of Niagara where the air is being drained!”

“Oh, devilish and infernal plot against the world!” said Gabriel, bitterly.  “Yet in essence, after all, no different from the system of ten years ago, which kept food and shelter, light and fuel, under lock and key—­and made the dollar the only key to fit the lock!  Yet this seems worse, somehow; and though I die for it, my last supreme blow shall be against such unutterable, such murderous villainy!  So then, comrades—­”

He paused, suddenly, as Kate laid a hand on his arm.

“Hark!  What’s that?” she whispered.

Outside, somewhere, a sound had made itself heard.  Then on the porch, a loose board creaked.

Gabriel sprang to his feet.  The others stood up and faced the door.

“In heaven’s name, what’s that outside?” demanded Craig.

On the instant, a heavy foot crashed through the panels of their door.  The door, burst open, flew back.

In the aperture, stood a man, in aviator’s dress, with another dimly visible behind him.  Both these men held long, blue-nosed, oxygen-bullet-shooting revolvers levelled at the little group around the table.

“My God!  Air Trust spies!” cried Grantham, pale as death.

“Hands up, you!” shouted the man in the doorway, with a wild triumph in his voice.  “You’re caught, all of you!  Not a move, you ——­ ——­ ——!  Hands up!”