“No.  Too noisy.  Run out to Englewood, to mine.  We’ll be quiet there.  And come early, Waldron.  We’ve no end of things to discuss.  The quicker we get the actual work under way, now, the better.  You can see Catherine, too.  Isn’t that an inducement?”

Thus ended the conference.  It resumed, that night, in Flint’s luxurious study at “Idle Hour,” his superb estate on the Palisades.  Waldron paid only a perfunctory court to Catherine, who manifested her pleasure by studied indifference.  Both magnates felt relieved when she withdrew.  They had other and larger matters under way than any dealing with the amenities of life.

Until past midnight the session in the study lasted, under the soft glow of the Billionaire’s reading-light.  And many choice cigars were smoked, many sheets of paper covered with diagrams and calculations, many vast schemes of conquest expanded, ere the two masters said good-night and separated.

At the very hour of Waldron’s leave-taking, another man was pondering deeply, studying the problem from quite another angle, and—­no less earnestly, than the two magnates—­laying careful plans.

This man, sturdy, well-built and keen, smoked an old briar as he worked.  A flannel shirt, open at the throat, showed a well-sinewed neck and powerful chest.  Under the inverted cone of a shaded incandescent in his room, at the electricians’ quarters of the Oakwood Heights enclosure, one could see the deep lines of thought and careful study crease his high and prominent brow.

From time to time he gazed out through the open window, off toward the whispering lines of surf on the eastern shores of Staten Island—­the surf forever talking, forever striving to give its mystic message to the unheeding ear of man.  And as he gazed, his blue eyes narrowed with the intensity of his thought.  Once, as though some sudden understanding had come to him, he smote the pine table with a corded fist, and swore below his breath.

It was past two in the morning when he finally rose, stretched, yawned and made ready for sleep on his hard iron bunk.

“Can it be?” he muttered, as he undressed.  “Can it be possible, or am I dreaming?  No—­this is no dream!  This is reality; and thank God, I understand.”

Then, before he extinguished his light, he took from the table the material he had been studying over, and put it beneath his pillow, where he could guard it safe till morning.

The thing he thus protected was none other than a small note-book, filled with diagrams, jottings and calculations, and bound in red morocco covers.

That night, at Englewood—­in the Billionaire’s home and in the workman’s simple room at Oakwood Heights—­history was being made.

The outcome, tragic and terrible, who could have foreseen?

CHAPTER IX.

DISCHARGED.

Almost all the following morning, working at his bench in the electro-chemical laboratories of the great Oakwood Heights plant, Gabriel Armstrong pondered deeply on the problems and responsibilities now opening out before him.