“Then your idea is that the United States is not concerned in the matter?” the Secretary asked.

“Not directly, yet it may be very much concerned in the result.  We will know more about it after Mr. Harleston has had his interview with the lady.”

“That’s so!” the Secretary reflected.  “We shall trust you, Harleston, to find out something definite from her.  Keep me advised if anything turns up.  It seems peculiar, and it may be only a personal matter and not an affaire d’etat.  At all events, you’ve a pleasant interview before you.”

“Maybe I have—­and maybe I haven’t!” Harleston laughed—­and he and Carpenter went out, passing the French Ambassador in the anteroom.

Harleston went straight to Police Headquarters.  The Chief was waiting for him.

“I had Thompson, your cab driver, here,” said Ranleigh, “and he tells a somewhat unusual but apparently straight tale; moreover, he is a very respectable negro, well known to the guards and the officers on duty around Dupont Circle, and they regard him as entirely trustworthy.  He says that last evening about nine o’clock, when he was jogging down Connecticut Avenue on his way home—­he owns his rig—­he was hailed by a fare in evening dress, top coat, and hat, who directed him to drive west on Massachusetts Avenue.  In the neighbourhood of Twenty-second Street, the fare signalled to stop and ordered him to come to the door.  There he asked him to hire the horse and cab until this morning, when they would be returned to him at that point.  Thompson naturally demurred; whereupon the man offered to deposit with him in cash the value of the horse and cab, to be refunded upon their return in the morning less fifty dollars for their hire.  This was too good to let slip and Thompson acquiesced, fixing the value at three hundred and fifty dollars, which sum the man skinned off a roll of yellow-backs.  Then the fare buttoned his coat around him, jumped on the box, and drove east on Massachusetts Avenue.  This morning the horse and cab were backed up to the curb at their customary stand in Dupont Circle, where they were found by officer Murphy shortly after daybreak; before he could report the absence of the driver, Thompson came up and explained.”

“Can Thompson describe the man?” Harleston asked.

“Merely that he was clean-shaved, medium-sized, somewhat stout, wore evening clothes, and was, apparently, a gentleman.  Thompson thinks however, that he could readily recognize the man, so we should let him have a look at the fellow that’s under guard in your apartment.”

“It isn’t he,” Harleston explained.  “He’s slender, with a mustache and imperial.  It was Marston, likely.  Did any of your officers see cab No. 333 between nine P.M. and this morning?”

“The reports are clean of No. 333, but we are investigating now.  It’s not likely, however.  Meanwhile, if there is anything else I can do, Mr. Harleston—­”