“My negligence!” Bernier, as pale as his face had been, flushed crimson. “My negligence! I have not budged from my lodge--not even from the corridor. I have always worn the key in my breast pocket and I swear to you that no one entered that room--no one at all--after you were there at five o’clock, except M. and Mme. Darzac, themselves. I do not count, of course, the few moments that you and M. Sainclair were there at about six o’clock.” “What!” exclaimed Rouletabille. “Do you want me to believe that this individual--you have forgotten his name, I think, Bernier--let us call him ‘the Man’--that the man was killed in M. Darzac’s rooms if he was not there?” “I do not. And, furthermore, I can swear to you that he _was_ there.” “Yes, but how could he have been? That is what I ask you, Bernier. And you are the only one who can answer because you alone had the key in the absence of M. and Mme. Darzac. And M. Darzac never took the key with him when he left the room and no one could have gotten into the room to hide while he was there.” “That is the mystery, monsieur. That is what puzzles M. Darzac more than all the rest. But I have only been able to answer him as I have answered you. There is the mystery.” “When you left the room with M. Darzac, M. Sainclair and myself at about a quarter after six, did you lock the door immediately?” “Yes, monsieur.” “When did you open it after that?” “Not at all.” “And where were you in the meantime?” “In front of the door of my lodge, watching the door of the apartment. My wife and I took our dinner in that same spot at about half after six, on a little table in the corridor, because, on account of the door of the tower being open, it was quite light and was pleasanter. After dinner, I sat in the doorway of the lodge, smoking a cigarette and chatting with my wife. We were so seated that, even if we had wished to do so, we would not have been able to withdraw our eyes from M. Darzac’s rooms. It is a mystery!--a mystery more extraordinary than the mystery of the Yellow Room. For, in the former case, we did not know of what had passed _before_. But now, monsieur, one knows all that happened beforehand since you yourself visited the apartment at 5 o’clock and saw that no person was there; one knows all that passed during the interim, for either I had the key in my pocket, or M. Darzac was in his room and must have seen the man who opened his door and entered the room for the purpose of assassinating him. And while I was sitting in the corridor before the door, I must have seen the man pass! And we know what took place _after_. After, there was the death of the man and that proved that the man was there. Ah, it is a mystery!” “And from five o’clock until the moment of the tragedy, you declare that you never quitted the corridor?” “I swear it.” “You are absolutely certain?” persisted Rouletabille. “Ah, pardon, monsieur--there was one moment--the moment that you called me.”