two A.M.
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 ? ''