“Did you ever see it before?”

“I am not certain,” she replied.  “I have seen one very much like it.”  Her tone was troubled.  She glanced at me as if for help, but I was powerless.

“Where?” The detective was watching her closely.  At that moment there came an interruption.  The door opened without ceremony, and Johnson ushered in a tall, blond man, a stranger to all of us:  I glanced at Alison; she was pale, but composed and scornful.  She met the new-comer’s eyes full, and, caught unawares, he took a hasty backward step.

“Sit down, Mr. Sullivan,” McKnight beamed cordially.  “Have a cigar?  I beg your pardon, Alison, do you mind this smoke?”

“Not at all,” she said composedly.  Sullivan had had a second to sound his bearings.

“No—­no, thanks,” he mumbled.  “If you will be good enough to explain—­”

“But that’s what you’re to do,” McKnight said cheerfully, pulling up a chair.  “You’ve got the most attentive audience you could ask.  These two gentlemen are detectives from Pittsburg, and we are all curious to know the finer details of what happened on the car Ontario two weeks ago, the night your father-in-law was murdered.”  Sullivan gripped the arms of his chair.  “We are not prejudiced, either.  The gentlemen from Pittsburg are betting on Mr. Blakeley, over there.  Mr. Hotchkiss, the gentleman by the radiator, is ready to place ten to one odds on you.  And some of us have still other theories.”

“Gentlemen,” Sullivan said slowly, “I give you my word of honor that I did not kill Simon Harrington, and that I do not know who did.”

“Fiddlededee!” cried Hotchkiss, bustling forward.  “Why, I can tell you—­” But McKnight pushed him firmly into a chair and held him there.

“I am ready to plead guilty to the larceny,” Sullivan went on.  “I took Mr. Blakeley’s clothes, I admit.  If I can reimburse him in any way for the inconvenience-”

The stout detective was listening with his mouth open.  “Do you mean to say,” he demanded, “that you got into Mr. Blakeley’s berth, as he contends, took his clothes and forged notes, and left the train before the wreck?”

“Yes.”

“The notes, then?”

“I gave them to Bronson yesterday.  Much good they did him!” bitterly.  We were all silent for a moment.  The two detectives were adjusting themselves with difficulty to a new point of view; Sullivan was looking dejectedly at the floor, his hands hanging loose between his knees.  I was watching Alison; from where I stood, behind her, I could almost touch the soft hair behind her ear.

“I have no intention of pressing any charge against you,” I said with forced civility, for my hands were itching to get at him, “if you will give us a clear account of what happened on the Ontario that night.”

Sullivan raised his handsome, haggard head and looked around at me.  “I’ve seen you before, haven’t I?” he asked.  “Weren’t you an uninvited guest at the Laurels a few days—­or nights—­ago?  The cat, you remember, and the rug that slipped?”