There is no treasure to be found here. All you see is filth. Dirty murky water and fumes rising from it burns your eyes. You see animals roaming around. Are they small dogs? No they are rodents, big rats. They glisten with the filth they are covered with. It is dark and difficult to see much else.
sewer entrance, Inside Tower
a rat chews on a dropped hymnbook
snakes
I am a snake. Snakes are not regarded as important in the realm. I kill rodents and chickens.
hissssssssss.   I spy my next meal. Is that a snake I hear... a... a...a....snake... hisssssss, it's nothing rat, keep chewing. No! Get away! Away! You cannot catch me.  You are too big and fat to run fast.  You will be mine I hope you are poisoned by the mold I consumed.  If it didn't bother you it won't bother me. Who knows... hisss, well i guesssss thisssss is it then. For you... you have no idea what you have gotten yourself into  we shall see I bite you, and you will be ill!