With a sudden gusty chatter, the engine caught.  A great wind sprang up, from the roaring, whirling blades.  The Floriot rolled easily forward, speeded up, and gathered headway.

Gabriel suddenly rotated the rising-plane.  The great gull soared, careened and took the air with majestic power.  The watchers on the mountain-side saw its hooded lights, that glowed upon its compass and barometric-gauge, slowly spiralling upward, ever upward, as Gabriel climbed with his two passengers.

Then the lights sped forward, northward, in a long tangent, and, as they swiftly diminished to mere specks, the echo of a farewell hail drifted downward from the black and star-dusted emptiness above.

Craig turned to Grantham, when the last gleam of light had faded in a swift trajectory.

“God grant they reach the last remaining refuge safely!” said he, with deep emotion.  “And may their flight be quick and sure!  For the fate of the world, its hope and its salvation from infinite enslavement, are whirling through the trackless wastes of air, to-night!”

CHAPTER XXXII.

OMINOUS DEVELOPMENTS.

The first intimation that Flint and Waldron had of any opposition to their plans, of any revolt, of any danger, was at quarter past three on the afternoon of October 8th, 1925.  All that afternoon, busy with their final plans for the immediate extension of their system, they had been going over certain data with Herzog, receiving reports from branch managers and conferring with the Congressional committee that—­together with Dillon Slade, their secret-service tool, now also President Supple’s private secretary—­they had peremptorily summoned from Washington to receive instructions.

In the more than four years that had passed since they had put Gabriel behind bars—­years fruitful in strikes and lockouts, in prostitutions of justice, in sluggings and crude massacres—­both men had altered notably.

Though the National Censorship now no longer permitted any cartooning of a “seditious” nature, i.e., representing any of the Air Trust notables, old Flint’s features tempted the artist’s pencil more than ever.  Save for a little white fringe of hair at the back of his head, he had become almost bald, thus adding greatly to his strong suggestion of a vulture.  His face was now more yellow and shrunken than ever, due to a rather heavier consumption of his favorite drug, morphine; his nose had hooked more strongly, and his one gold tooth of other days now had two more to bear it company.  His eyes, too, behind his thick pince-nez, had grown more shifty, cold and cruelly calculating.  If it be possible to conceive a fox, a buzzard and a jackal merged in one, old Isaac Flint today represented that unnatural and hideous hybrid.

Now, as he stood facing “Tiger” Waldron, in the inner and sancrosanct office of the Air Trust plant at Niagara—­the office that even the President of these United States approached with deference and due humility—­the snarl on his face revealed the beast-soul of the man.