I looked and saw Mademoiselle start from her companion in anger, stung by his words; but he caught her arm almost fiercely, and drew her to him. I could see the white face she turned to right and left. “I will end it,” said Fronsac, and stepped from the shadow, musket to shoulder. But I sprang after him and pulled it down. “Not that!” I cried. “Not that! That would ruin everything! The garrison would be upon us in a moment!” He looked at me with working face. “What then?” he asked. “Quick, Marsan, what then?” “We must surprise him,” I said. “We must gain the parapet. I too have an account to settle with that scoundrel!” “But how?” he demanded. “Quick!” “The tower!” I cried. He hastened after me back to the door. I took care to lock it behind us--at least, we would be secure against surprise from that direction. Then we sped up the stair--up and up. At last, peering from one of the narrow windows, I saw we were on a level with the parapet, but there was no door--only the solid wall of stone. Fronsac was cursing softly to himself. “You should have let me end it down below!” he cried. “Now we shall be too late!” “Come, there must be some way,” I muttered in perplexity. “Let us go down a flight.” We retraced our steps, quivering with impatience. But a cry of joy burst from Fronsac as we gained the lower floor. “There is a door!” he said. And, sure enough, there it was--a little door of oak, set firmly in the masonry. I held the torch near it and examined it intently. “Well, we must pause here,” I said at last, “unless, by chance, Drouet carried a key to this also. Let us see.” I ran rapidly through the bunch I had taken from him, trying one after another, but not one would throw back the bolt. “Come, let us go down again,” cried Fronsac. “I have still the musket,” and he started down the stair. I caught at the door and pulled at it savagely. It swung open in my hand. Then I saw what fools we had been. Small wonder none of our keys would throw the bolt, since it was already thrown! Roquefort must have passed that way to gain the parapet. Then he must still be there! And my heart was beating savagely as we stole through the door and up a short flight of steps. In a moment I saw the stars above me and felt the fresh air of the night upon my face. Darkness had come in earnest, and even here, high on the parapet, there was only the dim light of the stars. I feared that at the first turn we should run into a sentry, but we had no time to waste in hesitation. “Do not fire!” I cautioned Fronsac. “What we do must be done silently,” and gripping my poniard--Drouet’s poniard--tightly, I stepped out. For a moment I could see nothing, and then, away in front of us, I caught a glimpse of two dim figures. Fronsac saw them in the same instant, and would have sprung forward but that I held him back.