http://www.ttlg.com/forums/forumdisplay.php?f=133
This place might help. Your problem is a common one, DS, and far as I can remember you just had to frob(using use-button) througt the books at the tables of the Keeper library, and one of them should open and add a note about the Kurshok Citadel. Then the way opens to the sewers. It's in the docks, a grating leading to the sewers should be open.
"Two clicks for the old kings"