A section of the wall above him creaked and slid away.
He put his shoulder against the wall and a section slid aside.
A section of the wall slid aside to form a doorway.
It must double as a switch, for a section of wall slid aside.
The upper section of the ladder should slide easily up and down.
There was a whirring sound, and a section of the office wall slid open.
At his order, a section of the wall slid open to reveal a viewer.
The outer door closed, the section of wall slid away, and a man stepped through.
A section of the wall slid back to admit the newcomer.
A section slid under the weight but somehow did not collapse.