in spite of the barking of a chained-up dog

Then D'Artagnan became almost wild. He ran along the high road, took the path he had before taken, and reaching the ferry, interrogated the boatman.
About seven o'clock in the evening, the boatman had taken over a young woman, wrapped in a black mantle, who appeared to be very anxious not to be recognized; but entirely on account of her precautions, the boatman had paid more attention to her and discovered that she was young and pretty.
There were then, as now, a crowd of young and pretty women who came to St. Cloud, and who had reasons for not being seen, and yet D'Artagnan did not for an instant doubt that it was Mme. Bonacieux whom the boatman had noticed.
D'Artagnan took advantage of the lamp which burned in the cabin of the ferryman to read the billet of Mme. Bonacieux once again, and satisfy himself that he had not been mistaken, that the appointment was at St. Cloud and not elsewhere, before the D'Estrees's pavilion and not in another street. Everything conspired to prove to D'Artagnan that his presentiments had not deceived him, and that a great misfortune had happened.
He again ran back to the chateau. It appeared to him that something might have happened at the pavilion in his absence, and that fresh information awaited him. The lane was still deserted, and the same calm soft light shone through the window.
D'Artagnan then thought of that cottage, silent and obscure, which had no doubt seen all, and could tell its tale. The gate of the enclosure was shut; but he leaped over the hedge, and in spite of the barking of a chained-up dog, went up to the cabin.
No one answered to his first knocking. A silence of death reigned in the cabin as in the pavilion; but as the cabin was his last resource, he knocked again.
It soon appeared to him that he heard a slight noise within--a timid noise which seemed to tremble lest it should be heard.
Then D'Artagnan ceased knocking, and prayed with an accent so full of anxiety and promises, terror and cajolery, that his voice was of a nature to reassure the most fearful. At length an old, worm-eaten shutter was opened, or rather pushed ajar, but closed again as soon as the light from a miserable lamp which burned in the corner had shone upon the baldric, sword belt, and pistol pommels of D'Artagnan. Nevertheless, rapid as the movement had been, D'Artagnan had had time to get a glimpse of the head of an old man.
"In the name of heaven!" cried he, "listen to me; I have been waiting for someone who has not come. I am dying with anxiety. Has anything particular happened in the neighborhood? Speak!"
The window was again opened slowly, and the same face appeared, only it was now still more pale than before.
D'Artagnan related his story simply, with the omission of names. He told how he had a rendezvous with a young woman before that pavilion, and how, not seeing her come, he had climbed the linden tree, and by the light of the lamp had seen the disorder of the chamber.
The old man listened attentively, making a sign only that it was all so; and then, when D'Artagnan had ended, he shook his head with an air that announced nothing good.