“Gentlemen,” he said, his face ghastly, “it is of no use for me to attempt a denial.  The dagger and necklace belonged to my sister, Alice Curtis!”

CHAPTER XXXI

AND ONLY ONE ARM

Hotchkiss was the first to break the tension.

“Mr. Sullivan,” he asked suddenly, “was your sister left-handed?”

“Yes.”

Hotchkiss put away his note-book and looked around with an air of triumphant vindication.  It gave us a chance to smile and look relieved.  After all, Mrs. Curtis was dead.  It was the happiest solution of the unhappy affair.  McKnight brought Sullivan some whisky, and he braced up a little.

“I learned through the papers that my wife was in a Baltimore hospital, and yesterday I ventured there to see her.  I felt if she would help me to keep straight, that now, with her father and my sister both dead, we might be happy together.

“I understand now what puzzled me then.  It seemed that my sister went into the next car and tried to make my wife promise not to interfere.  But Ida—­Mrs. Sullivan—­was firm, of course.  She said her father had papers, certificates and so on, that would stop the marriage at once.

“She said, also, that her father was in our car, and that there would be the mischief to pay in the morning.  It was probably when my sister tried to get the papers that he awakened, and she had to do—­what she did.”

It was over.  Save for a technicality or two, I was a free man.  Alison rose quietly and prepared to go; the men stood to let her pass, save Sullivan who sat crouched in his chair, his face buried in his hands.  Hotchkiss, who had been tapping the desk with his pencil, looked up abruptly and pointed the pencil at me.

“If all this is true, and I believe it is,—­then who was in the house next door, Blakeley, the night you and Mr. Johnson searched?  You remember, you said it was a woman’s hand at the trap door.”

I glanced hastily at Johnson, whose face was impassive.  He had his hand on the knob of the door and he opened it before he spoke.

“There were a number of scratches on Mrs. Conway’s right hand,” he observed to the room in general.  “Her wrist was bandaged and badly bruised.”

He went out then, but he turned as he closed the door and threw at me a glance of half-amused, half-contemptuous tolerance.

McKnight saw Alison, with Mrs. Dallas, to their carriage, and came back again.  The gathering in the office was breaking up.  Sullivan, looking worn and old, was standing by the window, staring at the broken necklace in his hand.  When he saw me watching him, he put it on the desk and picked up his hat.

“If I can not do anything more—­” he hesitated.

“I think you have done about enough,” I replied grimly, and he went out.

I believe that Richey and Hotchkiss led me somewhere to dinner, and that, for fear I would be lonely without him, they sent for Johnson.  And I recall a spirited discussion in which Hotchkiss told the detective that he could manage certain cases, but that he lacked induction.  Richey and I were mainly silent.  My thoughts would slip ahead to that hour, later in the evening, when I should see Alison again.