SPOILER...
There are two separate rooms, each with one lever -- pulling one opens
the big door with the small little hole (small enough to click on an
enemy's leg and deliver some weapon damage), the other should reveal the
throne room. If you managed to find a letter, you should have gotten a
hint that there is a secret switch to open a hidden door within the
throne room. How does one remain seated and still be able to open a
secret door? You guessed it...
GEORGE