“Did Miss Langmore see anybody?”

“She saw a Doctor Bird pass in his buggy and a farmer named Carboy go by on foot.”

“When was this?”

“While she was at the piano.  She doesn’t know the exact time.”

There was a pause and the detective gave a faraway look out of the window and down the bustling thoroughfare.

“So far as you are aware, Mr. Case, did Mr. Langmore have any personal enemies?”

“I never heard of any.”

“He was rich?”

“Yes.”

“What was his business?”

“He was a dealer in patents and a promoter.  Some thought he was rather eccentric, but I never found him so.  He used to have an office here in New York but gave that up a year ago.”

“Well, what is your idea of this crime?”

“I haven’t any.  But I know Margaret Langmore is not guilty.”

“Evidently if they suspect her they have concluded that Mrs. Langmore was killed first.”

“That is their idea, but it looks to me as if both were killed at about the same time, although I know that couldn’t very well be.”

“No, not if one was upstairs and the other down.  Do you think it possible that one killed the other and then committed suicide?”

At this Raymond Case started back.

“I had not thought of that!” he cried.  “If it is true then that clears Margaret.”  Evidently he was thinking only of the girl he loved—­everything else concerning the mystery was of secondary consideration.

“Such a thing is possible, although not probable, unless the two had a bitter quarrel between themselves.  Every crime must have a motive.  People do not commit murder unless there is a reason for it or unless they are insane.  Motives may be divided into three classes—­jealousy, revenge, or gain.  In this instance I think we can throw out jealousy—­”

“Mrs. Langmore was jealous of Margaret.”

“And wasn’t the young lady jealous of her stepmother in a way?”

“But she is not guilty—­I’ll stake my life on her innocence.”

“Then let us come down to revenge or gain.  You say nothing was stolen.  Was there a safe in the house?”

“Yes, and it is closed, and will remain so until the experts open it.”

“Nobody knew the combination but Mr. Langmore?”

“That’s it.  Margaret did know, but her stepmother had her father change the combination and keep it to himself.”

“Had he much money in the house?”

“I think not.  Margaret says her father was in the habit of depositing cash in the bank as soon as he received it.”

“What sort of promoting did he do?”

“He organized companies to manufacture his patents.  He also speculated in real estate and in mortgages.  He owned two buildings in this city and several in the country.”

“Who are the other members of the family?”

“Margaret’s married sister, Mrs. Andrew Wetherby, of Sanhope, and Mrs. Langmore’s two sons, Tom and Dick Ostrello.”