"Well, your man was a woman--and she was accidentally deliberately careful that I shouldn't see her face."

"H-u-m!" said Harleston. "Young or old?"

"She's got ripples enough on her gown to be sixty, and figure enough to be twenty."

"Slender?"

"Yes; a perfect peach!"

"How's her walk?"

"As if the ground was all hers."

"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 'h.e.l.lo.'"

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

The episode of the cab of the sleeping horse was leading on to--what?

Three men in the Collingwood knew of the occurrence, yet no one had come in or gone out, and no one had telephoned. Moreover, they also knew of Harleston's part in the matter. The girl had not lied, he was sure; therefore they must have gained entrance from the outside; and, possibly, were now hiding in the Chartrand apartment--if the telephone message to No. 401 had to do with the occupant of the deserted cab and the lost letter. Yet how to connect things? And why bother to connect them?

He did not care for the vanished lady of the cab--he had the letter and the photograph; and because of them he was to have a talk with an interesting young woman at five o'clock that afternoon. The cipher letter, which was the much desired quant.i.ty, was safely across the hall, waiting to be turned over to Carpenter, the expert of the State Department, for translation. Meanwhile, what concerned Harleston was the photograph of Madeline Spencer and her connection with the case--and to know if the United States was concerned in the affair.

At this point he turned over and calmly went to sleep. Tomorrow was another day.

He was aroused by a vigorous pounding on the corridor door. It was seven-thirty o'clock. He yawned and responded to the summons--which grew more insistent with every pound.

It was Stuart--the envelope and the flowers in his hand.

"Scarcely heard your gentle tap," Harleston remarked. "Why don't you knock like a man?"

"Here's your d.a.m.n bouquet, also your envelope," said Stuart, "You probably don't recall that you left them with me about two this morning.

I _do_."

"I'm mighty much obliged, old man," Harleston responded. "You did me a great service by taking them--I'll tell you about it later."

"Hump!" grunted Stuart. "I hope you'll come around to tell me at a more seasonable hour. So long!"

Harleston closed the door, and was half-way across the living-room when there came another knock.

Tossing the envelope and the faded roses on a nearby table, he stepped back and swung open the door.

Instantly, a revolver was shoved into his face, and Crenshaw sprang into the hall and closed the door.

"I thought as much!" he exclaimed. "I'll take that envelope, my friend, and be quick about it."

"What envelope?" Harleston inquired pleasantly, never seeming to notice the menacing automatic.

"Come, no trifling!" Crenshaw snapped. "The envelope that the man from the apartment across the corridor just handed you."