by littlebro » Tue Dec 17, 2013 8:39 am
You can't access that door at the moment, so leave it.
To put out the fires, you need to have visited all the rooms where there are 'ghost' events shown in cut scenes. This means that until you have done a fair bit of exploring you can't get past them.
EDIT
I'm assuming that when you say 'Nimrod's Castle' you mean the abandoned fort fairly early on in the game. Is that right? Or do you mean the Castle? Your reference to the well made me thing you were near the beginning of the game, but perhaps that's wrong?