I went to the wall in the graveyard and Random comments that there could be a secret room.
Then I found the bust only a mother could love, and interacted with it to get the code.
Went back to the wall and Random says:
"... it should have been a secret room. Well obviously it persistently isn't"
Went back to the bust again, back to the wall again. Same result.
I must have done something wrong. Maybe I shouldn't have inspected the wall first. So quite a chunk of the game is closed to me.
