“That is a question which ought to be propounded to Professor Stangerson as well as to the rest of us,” interposed Arthur Rance, instantly. “For from the moment when we begin any course of reasoning along these lines, I can see no object in not having the Professor, who was at the table at luncheon with us on that day, here at this time also.” “Mr. Rance!” cried the Lady in Black. “Yes, I must repeat it, if you will pardon me,” replied Edith’s husband, haughtily. “Monsieur Rouletabille was wrong to generalize when he said, ‘All the members of the house party----’” “Professor Stangerson is so far from us in spirit that I have no need of his presence here,” pronounced Rouletabille in a tone so stern and solemn that it fell impressively on the ears of each and every one among us. “Although Professor Stangerson had lived with us in the Château of Hercules, he was not one of us in regard to feeling the presence of Larsan on that day. And Larsan is here among us.” This time we stole stealthy glances at each other as though we suspected each other of stealing, and the idea that Larsan might really be among us appeared to me so mad that I exclaimed, forgetting that I had promised not to address Rouletabille: “But at that luncheon on the terrace, there was still another person whom I do not see here.” Rouletabille cast an angry look at me as he answered: “Still Prince Galitch! I have already told you, Sainclair, with what task the Prince is occupying himself on this frontier and I swear to you that it is not the trouble of Professor Stangerson’s daughter which concerns him. Leave Prince Galitch to his humanitarian labors!” “All that is not reasonable,” I remarked almost mechanically. “To tell the truth, Sainclair, your nonsense prevents me from reasoning.” But I had launched out, and, forgetting that I had promised Mme. Edith to defend Old Bob, I started in to attack him for the pleasure of proving Rouletabille in the wrong--and, besides, I felt, Edith would not bear rancor against me for very long. “Old Bob,” I began, in the clearest and most assured tones that I could command, “was also at that luncheon on the terrace and you take him entirely out of your calculations on account of this little ruby pin. But of what use is this little pin to prove to us that Old Bob was rowed away by Tullio, who waited for him at the orifice of a gallery leading from the shaft to the sea, if we cannot discover how Old Bob could, as he said, have gone by way of the shaft which we found closed from above and on the outside?” “Which _you_ found closed, you mean,” returned Rouletabille, fixing his eyes upon me with a strange expression which somehow embarrassed me. “I, on the contrary, found the shaft open. I had sent you after Mattoni and Pere Jacques. When you came back, you found me in the same place in the Court of the Bold, but I had had time to run to the shaft and find out that it had been opened.”