Rising, he made a sign to me to follow him, and, without in the least tying to conceal his movements or the sound of his footsteps, he led me through the gallery.

We reached the 'right' gallery and came to the landing-place which we crossed.
We then continued our way in the gallery of the left wing, passing Professor Stangerson's apartment.
At the far end of the gallery, before coming to the donjon, is the room occupied by Arthur Rance.

We knew that, because we had seen him at the window looking on to the court.

The door of the room opens on to the end of the gallery, exactly facing the east window, at the extremity of the 'right' gallery, where Rouletabille had placed Daddy Jacques, and commands an uninterrupted view of the gallery from end to end of the chateau.
"That 'off-turning' gallery," said Rouletabille, "I reserve for myself; when I tell you you'll come and take your place here." And he made me enter a little dark, triangular closet built in a bend of the wall, to the left of the door of Arthur Rance's room.

From this recess I could see all that occurred in the gallery as well as if I had been standing in front of Arthur Rance's door, and I could watch that door, too.