He pondered a moment, an ugly, crafty smile on those old lips of his; then, struck by sudden inspiration, laughed a dry, harsh laugh.

“The very thing!” he exulted, with the mirth of a vulture that has just found a peculiarly revolting mass of carrion.  “Fool that I was, not to have thought of it before!”

Hastily he withdrew the letter from the envelope, opened it, and with eager hand wrote three short sentences.  He read these over, nodded approval, and this time sealed and addressed the letter.  Then he pushed an electric button over the desk.

“Have this letter carried to this address at once,” he commanded Slawson.  “Mr. Dillon Slade, 432 Highland Avenue, Rutherford, N. J.  See?  Special delivery won’t do.  Have Sanders take it at once, in the racer.  No answer required.  And after you’ve seen it start on its way, come back here.  I want to go to bed.”

“Yes, sir.  All right, sir,” the valet bowed as he took the letter and departed.

Ten minutes later, he was back again, helping old Flint undress.

Long after the Billionaire was in bed, in the big, luxurious room, with its windows open toward the river—­the room guarded all night by armed men in the house and on the lawn outside—­he lay there thinking of his plot, chuckling to himself over its infernal cunning, and filled with joy at the prospects now opening out ahead of him.

“Two birds with one stone, this time, for sure,” he pondered.  “Ha!  They’ll try to beat old Isaac Flint at this or any other game, will they?  Man or woman, I don’t care which, they’ll never get away with it—­never, so long as life and breath remain in me!”

Then, soothed by these happy thoughts, and by a somewhat increased dosage of his drug, the Billionaire gradually and contentedly fell asleep, to dream of victory, and vengeance, and power.

Not in weeks had he slumbered so peacefully.

But for many hours after her father was asleep, Catherine sat at her window, in a silk kimono, and with fevered pulses and dry eyes, with throbbing heart and leaping pulses, thought long thoughts.

Sleepless she sat there, counting the hours tolled from the church-spire in the town, below.

Morning still found her at the window, her brain afire, her heart laid desolate and waste by the consuming struggle which, that night, had swept and ravaged it.

CHAPTER XXI.

GABRIEL, GOOD SAMARITAN.

On the evening of July third, a week later, Gabriel Armstrong found himself at Rochester, having tramped the hundred miles from Syracuse, by easy stages.  During this week, old Flint took good care not to reopen the subject of the break with Waldron; and his daughter, too, avoided it.  They two were apparently at an impasse regarding it.  But Flint inwardly rejoiced, knowing full well the plot now under way.  And though Waldron urged him to take some further action and force the issue, Flint bade him hold his peace, and wait, telling him all would yet be well.