“I see!” Harleston replied.  “What would you, as a woman, make her age—­being indifferent and strictly truthful?”

“Not over twenty-eight—­probably less!” she laughed.  “And I’ve a notion she’s some to look at, Mr. Harleston.”

“You mean she’s a beauty?”

“Sure.”

“Call me if she comes back; also if any of the men go out.  They are strangers to the Collingwood so you will know them.”

“Very good, Mr. Harleston.”

He hung up the receiver and went back to bed.

If no one had come in and no one had left the Collingwood since his return, the men must have been in the building—­unless they had come by another way than the main entrance; which was the only entrance open after midnight.  If the former was the case, then someone on the outside must have communicated to them as to him.

With a muttered curse on his stupidity, he returned to the telephone.

“Miss Williams,” said he, “there has been a queer occurrence in the building since two A.M., and I should like to know confidentially whether any one has communicated with an apartment since one thirty.”

The girl knew that Harleston was on intimate terms with the State Department, and with the police, and she answered at once.

“Save only yours, not a single in or out call has been registered since twelve fifty-two when apartment No. 401 was connected for a short while.”

“Who has No. 401?”

“A Mr. and Mrs. Chartrand.  It’s one of the transient apartments; and they have occupied it only a few days.”

“You didn’t by any chance overhear—­”

“The conversation?” she laughed.  “Sure, I heard it; anything to put in the time during the night.  It was very brief, however; something about him being here, and to meet him at ten in the morning.”

“Who were talking?”

“Mrs. Chartrand and a man—­at least I took it to be Mrs. Chartrand; it was a woman’s voice.”

“Did they mention where they were to meet, or the name of the man?”

“No.  The very vagueness of the talk made its impression on me at that time of night.  In the daytime, I would not have even listened.”

“I understand,” said Harleston.  “Call me up, will you, if there are any developments as to the men I’ve described—­or the conversation.  Meanwhile, Miss Williams, not a word.”

“Not a word, Mr. Harleston—­and thank you.”

“What for?”

“For treating me as a human being.  Most persons treat me like an automaton or a bit of dirt.  You’re different; most of the men are not so bad; it’s the women, Mr. Harleston, the women!  Good-night, sir.  I’ll call you if anything turns up.”

“All of which shows,” reflected Harleston, as he returned to bed, “that the telephone people are right in asking you to smile when you say ‘hello.’”

It was a very interesting condition of affairs that confronted him.