"No, only there is the passage running on from this room."
Either this passage ran on to the outside or to another foot room.
The passage ran a dozen feet; then turned to the right.
This long passage ran the full length of the house, from front to back.
They had come to the passage running at right angles to the hall.
This passage ran above the rear of the great hall below.
Apparently the passage ran the whole length of the house.
The passage ran straight with no doors along its walls.
How do you know that this passage does not run straight to our destination?
It opened on a corridor, empty, the passage running to either side.