“Sit down there at the desk, Billy, and I’ll tell you,” said David Ellsworth; and then, as Billy Kane obeyed, he stepped swiftly across the room, opened the hall door, looked out, closed the door softly again, and from there walked to one of the two doors at the lower end of the room, opened this, looked into the room beyond, and closed it again.

Billy Kane watched the other in frank amazement. The door that David Ellsworth had just opened was the door of the “office”—the room that during working hours, which were from ten to five, was occupied by the stenographer. True, the room opened on the back hallway and had a separate entrance from the courtyard in the rear, an entrance always used by the stenographer, but it was always locked by Peters, the butler, at night, and he, Billy Kane, had the only other key.

David Ellsworth returned, and halted before Billy Kane’s chair.

“No, I am not in my second childhood, Billy,” he said quietly. “That letter was certainly not written without a purpose; and yet from every angle that I have been able to view it, except one, it would have been exactly that—without purpose. I believe it is the first step in a carefully laid plan that will divert, or fix, suspicion upon you.”

Billy Kane shook his head in perplexity.

“A plan?” he repeated. “I don’t understand.”

David Ellsworth’s only reply was to jerk his head significantly toward the other of the two doors at the end of the room.

Mechanically Billy Kane followed the direction of the gesture with his eyes; and then he was on his feet, his face suddenly grim and set.

“My God!” he murmured under his breath. “You mean——”

“Yes,” said David Ellsworth evenly. “Why not? I couldn’t tell you myself exactly how much those stones in there are worth, but they are ranked as one of the most valuable single collections of rubies in existence, and certainly the figures would run somewhere between two and three hundred thousand dollars. Besides, there’s always a little cash there—you know better than I do precisely how much at the present moment.”