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."