"No, sir."
"Hm! It must have been the thunder. Now tell me this, could anyone have passed you in the corridor while you stood at the banquet-room door without your knowing it?"
Joseph's round, red face spread into a grin. "The corridor is narrow, sir, and I"—he looked down complacently at his ample form—"I pretty well fill it up, don't I, sir?"
"You certainly do. Give me a sheet of paper." And with a few rapid pencil strokes the commissary drew a rough plan of the banquet room, the corridor, and the seven private dining rooms. He marked carefully the two doors leading from the banquet room into the corridor, the one where Joseph listened, opposite Number Four, and the one opposite Number Six.
"Here you are, blocking the corridor at Number Four"; he made a mark on the plan at that point. "By the way, are there any other exits from the banquet room except these two corridor doors?"
"No, sir."
"Good! Now pay attention. While you were listening at this door—I'll mark it A—with your back turned to Number Six, a person might have left the banquet room by the farther door—I'll mark it B—and stepped across the corridor into Number Six without your seeing him. Isn't that true?"
"Yes, sir, it's possible."
"Or a person might have gone into Number Six from either Number Five or Number Seven without your seeing him?"
