From the WT:
"From the silver tray on the table take the entrance card of the house. Examine the card in your inventory.
Turn around and go up the stairs at the right side of the table. Walk a little to the right and open the first door at the left side. Open the right door of the cupboard. Examine the plug and remember that you can find it here. You are going to need it later."
Dutch: did you turn around from the table where you pick up the card and......
The cupboard is on the right of the sink.