A hidden door was disclosed in the surface of the wall.
In other words, they served as a hidden inner door.
When she reached the first landing, the hidden door in the wall opened.
It is the hidden door that leads to the open road.
"If she had, one of them might show where the hidden door is."
Show us where some other carpenter might have put a hidden door.
Beyond that lay the hidden door through which the sun entered each morning.
The hidden doors are here somewhere, they have to be.
If she hadn't started over to the hidden door, she'd be under the picture now.
A hidden door had just slid open in the stone wall close to us.