For your final test to become a knight, speak with Balasiel once more. He will read to you from the Book of Tasks a riddle on where to go next. This riddle leads you to the guards in Victory Square.
Speak with Baunise Southern San d'Oria (H-9) (on the parapet over Westgate) to obtain the Book of the West, and then to Cahaurme Southern San d'Oria (J-9) (on the parapet over Eastgate) to obtain the Book of the East. These books direct you to seek an item in Davoi to give to Balasiel.
You will require Sneak and Invisible in Davoi. Use Sneak on all water mobs and Invisible for all Orcs. Some Orcs will still aggro to 75 players, and you can be detected by them even while making your way through the river.