When playing, grab the teacup from the ghost, then go to the right and give it to the guard, grab the key, go back to the room where you got the teacup, head down, go to the temple and it will open. Go to the right door and grab the key, then enter the locked room. Go forward through the next door, grab the key, and go forward. Then you can open the door. Hope this helps, I didn't know what door you were talking about though so I just explained the whole game :.)