It was not till six o’clock that I left the chateau, taking with me the article hastily written by my friend in the little sitting-room which Monsieur Robert Darzac had placed at our disposal. The reporter was to sleep at the chateau, taking advantage of the to me inexplicable hospitality offered him by Monsieur Robert Darzac, to whom Monsieur Stangerson, in that sad time, left the care of all his domestic affairs. Nevertheless he insisted on accompanying me to the station at Epinay. In crossing the park, he said to me:

“Frederic is really very clever and has not belied his reputation. Do you know how he came to find Daddy Jacques’s boots?—Near the spot where we noticed the traces of the neat boots and the disappearance of the rough ones, there was a square hole, freshly made in the moist ground, where a stone had evidently been removed. Larsan searched for that stone without finding it, and at once imagined that it had been used by the murderer with which to sink the boots in the lake. Fred’s calculation was an excellent one, as the success of his search proves. That escaped me; but my mind was turned in another direction by the large number of false indications of his track which the murderer left, and by the measure of the black foot-marks corresponding with that of Daddy Jacques’s boots, which I had established without his suspecting it, on the floor of The Yellow Room. All which was a proof, in my eyes, that the murderer had sought to turn suspicion on to the old servant. Up to that point, Larsan and I are in accord; but no further. It is going to be a terrible matter; for I tell you he is working on wrong lines, and I—I, must fight him with nothing!”

I was surprised at the profoundly grave accent with which my young friend pronounced the last words.

He repeated:

“Yes terrible!—terrible! For it is fighting with nothing, when you have only an idea to fight with.”

At that moment we passed by the back of the chateau. Night had come. A window on the first floor was partly open. A feeble light came from it as well as some sounds which drew our attention. We approached until we had reached the side of a door that was situated just under the window. Rouletabille, in a low tone, made me understand, that this was the window of Mademoiselle Stangerson’s chamber. The sounds which had attracted our attention ceased, then were renewed for a moment, and then we heard stifled sobs. We were only able to catch these words, which reached us distinctly: “My poor Robert!”—Rouletabille whispered in my ear:

“If we only knew what was being said in that chamber, my inquiry would soon be finished.”

He looked about him. The darkness of the evening enveloped us; we could not see much beyond the narrow path bordered by trees, which ran behind the chateau. The sobs had ceased.

“If we can’t hear we may at least try to see,” said Rouletabille.

And, making a sign to me to deaden the sound of my steps, he led me across the path to the trunk of a tall beech tree, the white bole of which was visible in the darkness. This tree grew exactly in front of the window in which we were so much interested, its lower branches being on a level with the first floor of the chateau. From the height of those branches one might certainly see what was passing in Mademoiselle Stangerson’s chamber. Evidently that was what Rouletabille thought, for, enjoining me to remain hidden, he clasped the trunk with his vigorous arms and climbed up. I soon lost sight of him amid the branches, and then followed a deep silence. In front of me, the open window remained lighted, and I saw no shadow move across it. I listened, and presently from above me these words reached my ears:

“After you!”

“After you, pray!”

Somebody was overhead, speaking,—exchanging courtesies. What was my astonishment to see on the slippery column of the tree two human forms appear and quietly slip down to the ground. Rouletabille had mounted alone, and had returned with another.

“Good evening, Monsieur Sainclair!”

It was Frederic Larsan. The detective had already occupied the post of observation when my young friend had thought to reach it alone. Neither noticed my astonishment. I explained that to myself by the fact that they must have been witnesses of some tender and despairing scene between Mademoiselle Stangerson, lying in her bed, and Monsieur Darzac on his knees by her pillow. I guessed that each had drawn different conclusions from what they had seen. It was easy to see that the scene had strongly impressed Rouletabille in favour of Monsieur Robert Darzac; while, to Larsan, it showed nothing but consummate hypocrisy, acted with finished art by M............