is marked with a green dot. select the club symbol above the green buttons on the lock (at the far right).
to clarify, the final order of the combination from left to right is: diamond, star, heart, club.
push the long, grey button at the bottom to submit your answer.
the toilet lid will open when the correct combination is entered into the lock.
take the flat key inside the toilet bowl water.
return to the back room.
when you enter the room, examine the area where you first retrieved the white disc (behind the revealed secret door). if this area is closed off, go to the cupboard and click the wrench to turn the water 