The Ear in the Wall

by Arthur B. Reeve

He drew back to see what effect the intelligence had on us, then resumed slowly: "Yes, I've had my men out on the case. That is what they think. I believe she often executed little confidential commissions for Langhorne, sometimes things that took her on short trips out of town. There is a possibility that she may be on a mission of that sort. But I think—it's this Black Book case that involves her now."

"Langhorne wouldn't talk much about anything," I put in, hastily remembering his manner. "He may not be responsible—but from his actions I'd wager he knows more about her than appears."

"Just so," agreed Carton. "If my men can find out that she was the operator who 'listened in' and got the notes and the transcript of the Black Book, then she becomes a person of importance in the case and the fact must be known to others who are interested. Why," he pursued, "don't you see what it means? If she is out of the way, there is no one to swear to the accuracy of the notes in the record, no one to identify the voices—even if we do manage finally to locate the thing."

"Dorgan and the rest are certainly leaving nothing undone to shake the validity of the record," ruminated Kennedy, accepting for the moment at least Carton's explanation of the disappearance of Miss Blackwell. "Have you any idea what might have happened to her?"

Carton shook his head negatively. "There are several explanations," he replied slowly. "As far as we have been able to find out she led a model life, at home with her mother and sister. Except for the few commissions for Langhorne and lately when she was out rather late taking the detectaphone notes, she was very quiet,—in fact devoted to her mother and the education of her younger sister."

"What sort of place was it in which the receivers of the detectaphone were located—do you know?" asked Kennedy quickly.

"Yes, it seems to be a very respectable boardinghouse," answered Carton. "She came there with a grip about a week ago and hired a room, saying she was out of town a great deal. Just about the same time a young man, who posed as a student in electrical engineering at some school uptown, left. It must have been he who installed the detectaphone—perhaps with the aid of a waiter in Gastron's. At any rate, she seems to have been alone in the boarding-house—that is, I mean, not acquainted with any of the other guests—during the time when she was taking down the record. Dorgan traced the wires, outside the two buildings, to her rooms, but she was not there. In fact there was nothing there but a grip with a few articles that give no clue to anything. Somehow she must have heard of it, for no one knows anything about her, since then."

"Perhaps Langhorne is keeping her out of the way so that no one can tamper with her testimony," I suggested.

"It's possible," said Carton in a tone that showed that he did not believe in that explanation. "How about that safe robbery, Kennedy? Some of the papers hinted that she might have known something of that. I had a man down there watching, afterwards, but I had cautioned him to be careful and keep under cover. One of the elevator boys told him that the robbers had made a hole in the safe. What did he mean? Did you see it?"

Rapidly Kennedy sketched what we had done, telling the story of how the dynamometer had at least partly exonerated Betty Blackwell.