The act, which staggered me, did not appear to affect Rouletabille much. We returned to his room and, without even referring to what we had seen, he gave me his final instructions for the night. First we were to go to dinner; after dinner, I was to take my stand in the dark closet and wait there as long as it was necessary—to look out for what might happen.

“If you see anything before I do,” he explained, “you must let me know. If the man gets into the ‘right’ gallery by any other way than the ‘off-turning’ gallery, you will see him before I shall, because you have a view along the whole length of the ‘right’ gallery, while I can only command a view of the ‘off-turning’ gallery. All you need do to let me know is to undo the cord holding the curtain of the ‘right’ gallery window, nearest to the dark closet. The curtain will fall of itself and immediately leave a square of shadow where previously there had been a square of light. To do this, you need but stretch your hand out of the closet, I shall understand your signal perfectly.”

“And then?”

“Then you will see me coming round the corner of the ‘off-turning’ gallery.”

“What am I to do then?”

“You will immediately come towards me, behind the man; but I shall already be upon him, and shall have seen his face.”

I attempted a feeble smile.

“Why do you smile? Well, you may smile while you have the chance, but I swear you’ll have no time for that a few hours from now.

“And if the man escapes?”

“So much the better,” said Rouletabille, coolly, “I don’t want to capture him. He may take himself off any way he can. I will let him go—after I have seen his face. That’s all I want. I shall know afterwards what to do so that as far as Mademoiselle Stangerson is concerned he shall be dead to her even though he continues to live. If I took him alive, Mademoiselle Stangerson and Robert Darzac would, perhaps, never forgive me! And I wish to retain their good-will and respect.

“Seeing, as I have just now seen, Mademoiselle Stangerson pour a narcotic into her father’s glass, so that he might not be awake to interrupt the conversation she is going to have with her murderer, you can imagine she would not be grateful to me if I brought the man of The Yellow Room and the inexplicable gallery, bound and gagged, to her father. I realise now that if I am to save the unhappy lady, I must silence the man and not capture him. To kill a human being is no small thing. Besides, that’s not my business, unless the man himself makes it my business. On the other hand, to render him forever silent without the lady’s assent and confidence is to act on one’s own initiative and assumes a knowledge of everything with nothing for a basis. Fortunately, my friend, I have guessed, no, I have reasoned it all out. All that I ask of the man who is coming to-night is to bring me his face, so that it may enter—”

“Into the circle?”

“Exactly! And his face won’t surprise me!”

“But I thought you saw his face on the night when you sprang into the chamber?”

“Only imperfectly. The candle was on the floor; and, his beard—”

“Will he wear his beard this evening?”

“I think I can say for certain that he will. But the gallery is light and, now, I know—or—at least, my brain knows—and my eyes will see.”

“If we are here only to see him and let him escape, why are we armed?”

“Because, if the man of The Yellow Room and the inexplicable gallery knows that I know, he is capable of doing anything! We should then have to defend ourselves.”

“And you are sure he will come to-night?”

“As sure as that you are standing there! This morning, at half-past ten o’clock, Mademoiselle Stangerson, in the cleverest way in the world, arranged to have no nurses to-night. She gave them leave of absence for twenty-four hours, under some plausible pretexts, and did not desire anybody to be with her but her father, while they are away. Her father, who is to sleep in the boudoir, has gladly consented to the arrangement. Darzac’s departure and what he told me, as well as the extraordinary precautions Mademoiselle Stangerson is taking to be alone to-night leaves me no room for doubt. She has prepared the way for the coming of the man whom Darzac dreads.”

“That’s awful!”

“It is!”

“And what we saw her do was done to send her father to sleep?”

“Yes.”

“Then there are but two of us for to-night’s work?”

“Four; the concierge and his wife will watch at all hazards. I don’t set much value on them before—but the concierge may be useful after—if there’s to be any killing!”

“Then you think there may be?”

“If he wishes it.”

“Why haven’t you brought in Daddy Jacques?—Have you made no use of him to-day?”

“No,” replied Rouletabille sharply.

I kept silence for awhile, then, anxious to know his thoughts, I asked him point blank:

“Why not tell Arthur Rance?—He may be of great assistance to us?”

“Oh!” said Rouletabille crossly, “then you want to let everybody into Mademoiselle Stangerson’s secrets?—Come, let us go to dinner; it is time. This evening we dine in Frederic Larsan’s room,—at least, if he is not on the heels of Darzac. He sticks to him like a leech. But, anyhow, if he is not there now, I am quite sure he will be, to-night! He’s the one I am going to knock over!”

At this moment we heard a noise in the room near us.

“It must be he,” said Rouletabille.

“I forgot to ask you,” I said, “if we are to make any allusion to to-night’s business when we are with this policeman. I take it we are not. Is that so?”

“Evidently. We are going to operate alone, on our own personal account.”

“So that all the glory will be ours?”

Rouletabille laughed.

We dined with Frederic Larsan in his room. He told us he had just come in and invited us to be seated at table. We ate our dinner in the best of humours, and I had no difficulty in appreciating the feelings of certainty which both Rouletabille and Larsan felt. Rouletabille told the great Fred that I had come on a chance visit, and that he had asked me to stay and help him in the heavy batch of writing he had to get through for the “Epoque.” I was going back to Paris, he said, by the eleven o’clock train, taking his “copy,” which took a story form, recounting the principal episodes in the mysteries of the Glandier. Larsan smiled at the explanation like a man who was not fooled and politely refrains from making the slightest remark on matters which did not concern him.

With infinite precautions as to the words they used, and even as to the tones of their voices, Larsan and Rouletabille discussed, for a long time, Mr. Arthur Rance’s appearance at the chateau, and his past in America, about which they expressed a desire to know more, at any rate, so far as his relations with the Stangersons. At one time, Larsan, who appeared to me to be unwell, said, with an effort:

“I think, Monsieur Rouletabille, that we’ve not much more to do at the Glandier, and that we sha’n’t sleep here many more nights.”

“I think so, too, Monsieur Fred.”

“Then you think the conclusion of the matter has been reached?”

“I think, indeed, that we have nothing more to find out,” replied Rouletabille.

“Have you found your criminal?” asked Larsan............