"The door is locked."
"Ah, yes. I thought so."
"Hullo!" came Sheffield's voice through the window, "who's there, Duquesne?"
"It is M. Lemage. M'sieur, allow me to make known the great Scotland Yard Inspector Sheffield."
With a queer parody of politeness, Duquesne turned the light of his lantern alternately upon the face of each, as he mentioned his name.
Sheffield bowed awkwardly. For he knew that he stood in the presence of the undisputed head of his profession—the first detective in Europe.
"You have not left the front door unguarded, M'sieur the Inspector?" inquired Lemage sharply.
"No, Mr. Lemage," snapped Sheffield, "I have not. My man Dawson is there, with an Agency man, too."
"Then we surround completely the room in which he is," declared Lemage.
Such was the case, as a glance at the following plan will show.