The doctor shook his head. "I have believed it to be Henry," he said simply.
"Not the hold-up?"
"Even that might have been,--though I confess that was the first event that gave me hope, because it gave me a doubt."
"Then I hold to my theory. Did Selby hold himself up, and afterwards, with Mrs. Bussey's connivance, get access to your surgery and hide his chain here under the hearth and his handkerchief behind your books? Does he write those typewritten accusations on your machine while Mrs. Bussey plays sentry? In that case, instead of being a short-sighted proceeding, as I at first thought, it is rather deep. The first intelligent investigation would throw suspicion upon Henry, who of course would have access to your room. In short, does Selby supply the venom, and Mrs. Bussey the easy, ignorant and vindictive tool? That's what is occupying my mind at present."
"Jumping Jerusalem!" gasped Dr. Underwood. "Aren't there some more tenable hypotheses that you have overlooked? Have you given due consideration to the possibility that Ben may be the son of an earl, stolen in childhood, with a strawberry mark on his arm, and Henry my first wife in disguise, and that I--Oh, I can't think of anything that would not be an anticlimax to your imaginative effort. What do you do for mental exercise when you are at home?"
But Burton refused to be diverted.
"I am willing to accept any other theory, but I am determined that the mystery shall be named and known. The police don't seem equal to it. I never had any experience in this direction, and I am not over-confident of my own abilities, but I am better than nothing, and I am going to do something,--something absurd, or futile, quite possibly, but at any rate something."
"If you succeed," said Dr. Underwood quietly, "you will have lifted the curse from my life and such a load from my heart as I pray you may never have to carry for an hour. If I were a king of the old style, I'd say: 'Ask what you will, even to the half of my kingdom.'"
Burton was about to make some light reply, when the sound of music from the old piano in the drawing-room came in between them. Leslie was playing. It was to the doctor's offer of half his kingdom what a spark is to a train of powder. The flashing thought it conjured up--though it was less a thought than a dazzling recognition--made him dizzy. He dropped his eyes, dismayingly conscious that it was a thought which he did not care to expose to the keen eyes of the old doctor. He stood silent for a moment, ostensibly listening to the music. Then he lifted his eyes, and put out his hand in farewell.
"Good night, Doctor. I shall go up to the Reservation to-morrow, and may not be back for a few days, but I'll leave my address at the hotel, in the event of your possibly wanting me. I'll say good night to Miss Underwood as I go out. I assume I'll find her if I follow the music."