up, down will go 5 down.
the solution: you start on 4 must get to 12. u (11), d (6), u (13), d (8), u (15), d (10), d (5), u (12).
the glass panel will open and you can take the special pipe key. go down the stairs again and when you’re in the service stairs, turn to the dining room. on the left side in the back is a door. it is locked by a key. use the brass key to unlock it and go through the door. you’re in the main staircase. look at the door in front of you. it’s closed with a latch. turn it so it’s 