Coquenil laughed at this candid judgment. "All the same, it has a bearing on our investigations."
"Diable!"
M. Paul reached for his glasses, rubbed them deliberately and put them on. "Papa Tignol," he said seriously, "I have come to a conclusion about this crime, but I haven't verified it. I am now going to give myself an intellectual treat."
"Wha-at?"
"I am going to prove practically whether my mind has grown rusty in the last two years."
"I wish you'd say things so a plain man can understand 'em," grumbled the other.
"You understand that we are in private room Number Seven, don't you? On the other side of that wall is private room Number Six where a man has just been shot. We know that, don't we? But the man who shot him was in this room, the little hair-brushing old maid saw the pistol thrown from this window, the dog found footprints coming from this room, the murderer went out through that door into the alleyway and then into the street. He couldn't have gone into the corridor because the door was locked on the outside."
"He might have gone into the corridor and locked the door after him," objected Tignol.
Coquenil shook his head. "He could have locked the door after him on the outside, not on the inside; but when we came in here, it was locked on the inside. No, sir, that door to the corridor has not been used this evening. The murderer bolted it on the inside when he entered from the alleyway and it wasn't unbolted until I unbolted it myself."
"Then how, in Heaven's name——"